# Optical Forums > Progressive Lens Discussion Forum >  More *Free-Form* Confusion!

## Fezz

There have been a few threads lately that have got me really thinking about the mass confusion over *Free-Form* progressives. Some posters have alluded to how easy of a sell they are, how basic the optics and math really are, how we should all be demonstrating how fantastic these lenses are. I stand by my statement that:

_"How can we expect a patient to understand the technology when many of us do not understand it?"_



I want to point out an example of the confusion that exists with *Free-Form* progressives. If the lens companies and the laboratories that process these *Free-Form* lenses can not be on the same page...................how can we?

I will use Seiko as an example, because I was reading a bunch of their material and CE information this morning.

The Seiko website lists the following seg heights for their lenses:

Succeed-17, 19
Succeed WS-15, 17
Supercede-16, 18
Supercede WS-14, 16

I will use two labs that are claiming to be all digital and that process these lenses in house, to show the descrepancies that exist!

Lab#1 
Succeed-?
Succeed WS-One sheet lists two minimums! 14, and 15!
Supercede-13*
Supercede WS-13*
*Minimum for both designs!

Lab#2
Succeed-15*
Succeed WS-15*
Supercede-14
Supercede WS-14
*"15mm fitting height for both designs"

As a sidenote: Both labs sent me information about the Supercede that states that Trivex and Trivex Transitions are an option. I called lab#1 and tried to order one..............well, they don't have it yet! So...why promote it I ask...........? I haven't called lab#2 yet, but their price and availability sheet is dated December 2008, and Trivex is listed.

So....what do you believe? Who is right?

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## Jacqui

I think we are going to see a lot of this. Most of these people don't really know what the H they are talking about, the technology is still too new.

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## Fezz

> I think we are going to see a lot of this. Most of these people don't really know what the H they are talking about, *the* *technology is still too new*.


Is it really all that new? 

Seiko has been producing these type lenses since 1996. Labs here in the US have been *manufacturing partners* for Seiko for quite a few years. I assume that Seiko and the other lens companies do a whole bunch of training, computer set-up, etc for these labs. I just find it amazing that something as simple as consistent minimum seg heights can not be found! How are we supposed to believe that the actual lens designs will be consistent?

 :Eek: :cheers::cheers:;):cheers::cheers::D

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## Fezz

We have to remember that the two labs that I am talking about are the ones beating the *Free-Form* drum the loudest. Their whole success rides on convincing us that either Seiko, Shamir, or Indo *Free-Form* progressives are the end all be all. They promote only two or three brands.

I would assume that Seiko, or Shamir, etc would have a little more concern about such descrepancies.

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## Fezz

> I just find it amazing that something as simple as consistent minimum seg heights can not be found! How are we supposed to believe that the actual lens designs will be consistent?


 
On top of all of this..............we are expected to believe that any compensated rx's and power readout slips are correct! Correct to what?


 :Eek: :cheers::shiner::cheers: :cry:

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## chip anderson

With these type lenses it would be difficult for us to tell easily if the stated seg. ht. had anything to do with the real world anyway. Until our skills and instrumentation are up to checking and evaluating them perhaps the "curve" is ahead of all of us, including the manufacturers.

Chip

Just a couriosity question, Daryl and Chilly Harry whom I believe to me smarter than most of us on these things.  Do you really understand these lenses both in theory and practice?

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## bob_f_aboc

> On top of all of this..............we are expected to believe that any compensated rx's and power readout slips are correct! Correct to what?
> 
> 
> :cheers::shiner::cheers:


I can only go by what I have heard/read on here and from the manufacturers and by the patient experiences that I have witnessed.

I have not tried the Seiko free-form product on my patients since the reaction I have had to the Seiko/Pentax AF lenses has been less than stellar. 

I have fit the Essilor 360 line and was not impressed with the results. HOYA's iD and iD Lifestyle have gotten pretty good results as well as the Kodak Unique. But, by far the best patient response has been with the Shamir Autograph II and Variable. I may not understand all of the science behind the lens, but I can't argue with the results that I personally have witnessed. 

Obviously, there is no such thing as the one lens that fits everyone. Someone else with a different fitting/measuring strategy for PAL's may have better success with another lens. At this point in the game, I think its best to find lenses that you are comfortable in fitting that are giving the patients as much of what they need as possible. All the 'education' from the manufacturers in the world is useless if the lens doesn't work for your patients and your practice.

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## Fezz

PS. Lab#2 has the Shamir Element listed as having a 15mm minimum fitting height! They are doing the Seiko products in Trivex.

 :Eek: :cheers: :Cool: :cheers: :cry:

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## bob_f_aboc

> Just a couriosity question, Daryl and Chilly Harry whom I believe to me smarter than most of us on these things. Do you really understand these lenses both in theory and practice?


 
I frimly believe that Harry and Daryl are cyborgs from the future here to help advance the standards of opticianry.  I think that between the two of them, they have all of the optical knowledge ever attained on Earth. Thank God we have them here!

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## Jacqui

*IMO*

I think that for the forseeable future we are going to see many differences in freeforms, same brand, style, etc. I think it's due to differing equipment and operators. Until things can be stabilized there are going to be differences between labs. I'm really not sure the lens companies actually know what's going on.

Also with out high tech measuring devices we cannot verify these lenses accurately. Maybe we need more Rotlex type units around to do it for us.

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## Fezz

Jacqui,
I think that I pick up what you are dropping.


Let me give you an example of what I think that you are getting at:

I have a patient that I want to put into a Supercede, or Auto II. This poor gal has 4.5 base up/4.5 base down. Lets assume that Lab#1 is going with a minimum 13 seg height, even though the manufacturer states 15, that they can do it, but they can not vary from the total prism power of 3 per eye(Seiko), or 4 per eye (Shamir)?

That is the scenario that I am dealing with. I am trying to get them to answer me why they can use a different seg height, but can not deviate from the prism.

**Sniff....sniff....sniff** Something stinks in *Free-FormVille*!!

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## Jacqui

> **Sniff....sniff....sniff** Something stinks in *Free-FormVille*!!


*Yes!!* Until labs and lens companies can get together and staighten things out there will be these problems. It may take a while :(

Where is AWTECH when we need him?? He has been making them about as long as anyone.

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## Fezz

> That is the scenario that I am dealing with. I am trying to get them to answer me why they can use a different seg height, but can not deviate from the prism.


 
I just spoke with one owner of one of the labs. He clearly stated that they alter seg heights "All day long"! I asked to explain then why he couldn't alter the prism. His response was that "The computer won't let us."!


Huh?

Sooooooooo...............................the computer will let them change the seg height, possibly *altering* the whole design of the lens, but it will not let them change the prism!

Oh yeah....................something *REALLY* stinks in *Free-FormVille*!!!

 :Cool: :cheers::cheers: :Confused: :cheers::cheers::D

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## Lee Prewitt

> On top of all of this..............we are expected to believe that any compensated rx's and power readout slips are correct! Correct to what?
> 
> 
> :cheers::shiner::cheers:


Hi Fezz,

I too had a problem with this until I remembered way back in the day when I had to compensate a high minus due to vertex changes. No one really does this anymore but then we did all the time.  The lenses would read completly different from the prescibed RX yet the patient saw just fine.  The compensated RX worked.  I trust today that the compensated RX that comes with the Shamir AutoII to be the equivalent of what was ordered.  Lo and behold...the compensated RX worked.

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## obxeyeguy

> Jacqui,
> I think that I pick up what you are dropping.
> 
> 
> Let me give you an example of what I think that you are getting at:
> 
> I have a patient that I want to put into a Supercede, or Auto II. This poor gal has 4.5 base up/4.5 base down. Lets assume that Lab#1 is going with a minimum 13 seg height, even though the manufacturer states 15, that they can do it, but they can not vary from the total prism power of 3 per eye(Seiko), or 4 per eye (Shamir)?
> 
> That is the scenario that I am dealing with. I am trying to get them to answer me why they can use a different seg height, but can not deviate from the prism.
> ...


....

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## chip anderson

I don't want to bad mouth any company today but I for one have had a number of compensated Power wraps, especially on progressive suns that definitely did not work.

Chip

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## HarryChiling

> I don't want to bad mouth any company today but I for one have had a number of compensated Power wraps, especially on progressive suns that definitely did not work.
> 
> Chip


Our office has only ordered 5 in total from various labs/manufacturers and none have worked. I am also told by the same people that have ZERO answers beyond what I can find in brochures that I wouldn't understand and that they are the experts pretty much in the same breath. The industry is basically witnessing another ball being dropped ladies and gentlemen. The product is beign catered to the vast majority of numb nuts that just don't know so wanyone with a golden tongue can field a call, but if you have any legitamte question that my stump someone the cold shoulder treatment comes out. Call me when we start applying this technology to traditional progressive blanks as this lab will be the one that truly understands the technology untill then they're all just implementing processes developed by someone else and their understanding is less than anyone here except for the tolerances they need to maintain and the mechanics of the equipment.  I'd say the only lab that understands the potential is the 3 Rivers lab that is seperatign the optics from the form, AWTECH has a neat idea with the blended lenticulars but so far I haven't meet anyone really impressed witht eh quality of the work.  The companies cleaning up optics are also the same companies that dirtied them up over the years so I am not impressed with their products for simply being able to clean up what they spent the better half of the last century convincing the industry is too expensive.

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## Fezz

Today I receive a flyer from Lab#1 that lists the Shamir Element.

Oddly, their listed minimum seg height is 16! Lab#2's msh for the Element is 15. I see that the listed Element fitting heights in the Frames Facts Lens Guide are 19 and 16 for the Element short.


Hmm?

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## chip anderson

Fezz:
As you know, everyone's technical department seldom reflects the advertising department.   Appearently advertising departments can do miracles compared to the technical people.

Chip

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## Fezz

:cheers::cheers::cheers:

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## Jacqui

> Today I receive a flyer from Lab#1 that lists the Shamir Element.
> 
> Oddly, their listed minimum seg height is 16! Lab#2's msh for the Element is 15. I see that the listed Element fitting heights in the Frames Facts Lens Guide are 19 and 16 for the Element short.
> 
> 
> Hmm?


As I said before, you're going to see this until all parties (design, software, equipment and fitting) get together and coordinate efforts.

As of right now they are suffering from non-linear waterfowl issues. :D

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## DragonLensmanWV

> Is it really all that new? 
> 
> Seiko has been producing these type lenses since 1996. Labs here in the US have been *manufacturing partners* for Seiko for quite a few years. I assume that Seiko and the other lens companies do a whole bunch of training, computer set-up, etc for these labs. I just find it amazing that something as simple as consistent minimum seg heights can not be found! How are we supposed to believe that the actual lens designs will be consistent?
> 
> :cheers::cheers:;):cheers::cheers::D


You mean like having old Progressive Identifier books that show lenses with a minimum of 24 hi, but the new books show the exact lens as now being able to be fit at 18 hi?
**

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## GAgal

I feel like somebody has their head up their bum. I just don't know if its me or the lab:hammer:I like to think that I am a reasonably intelligent person. I realize that coffee may be hot and that I should not use the hair dryer in the shower. I even understand the basics (very basic) of free form surfacing, but I don't understand how the labs can change the so called minimum seg height and still expect the same results. Minimum is minimum. When you cut 4mm off the "minimum" seg height, something is lost. I think that would be common sense  :Confused:  Maybe I'm wrong.

I agree with Jacqui that we are going to keep seeing this until all parties get together. Question is, when is that going to happen and can we make it happen sooner?

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## RT

> I even understand the basics (very basic) of free form surfacing, but I don't understand how the labs can change the so called minimum seg height and still expect the same results. Minimum is minimum. When you cut 4mm off the "minimum" seg height, something is lost.


I am unaware of this happening in any FreeForm or digitally surfaced lens.  In fact, one of the chief complaints about FreeForm as expressed by Optiboard posters is the _in_ability to make changes (i.e. change base curves, etc.).




> Today I receive a flyer from Lab#1 that lists the Shamir Element.
> 
> Oddly, their listed minimum seg height is 16! Lab#2's msh for the Element is 15. I see that the listed Element fitting heights in the Frames Facts Lens Guide are 19 and 16 for the Element short.


Is this a fundamental problem that is unique to FreeForm?  Has there never been confusion about the specifications for traditionally produced progressives?  It seems like the examples you've cited are all newly released designs, that happened to be produced using FreeForm.  I would think that confusion over specifications is a function of a design (traditional or FreeForm) that is new, not a function of how the back surface is produced.

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## Fezz

> I am unaware of this happening in any FreeForm or digitally surfaced lens. In fact, one of the chief complaints about FreeForm as expressed by Optiboard posters is the _in_ability to make changes (i.e. change base curves, etc.).


RT,

Please re-read my above posts, #11 and #13.

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## Fezz

Maybe I should just give up on all of this absurdity and just deal with Hoya for all of my *Free-Form* digital processing, digital surfacing, customized, individualized, mesmerized progressives!

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## RT

> Please re-read my above posts, #11 and #13.


I'm not sure I completely follow you.  Changing a seg height changes the FIT of a progressive, but not the design.  Labs are frequently faced with Rx orders (conventional and FreeForm) where real world constraints mean the job can't be made as ordered.  If the blank diameter isn't big enough to fill the frame at the requested seg height, either the ECP must select a different frame, change to a design that is available in a bigger blank, or change the seg height.  I can attest that labs frequently are requested to just change the seg height until the job will cut out of the available blank.  That is independent of whether the job is FreeForm vs conventional design, lined bifocal vs progressive, etc.

There ARE constraints on FreeForm processing that may not be present in conventional designs.  For example, the FreeForm process may have a physical limitation to the amount of prism that can be blocked or polished into the lens.  That's not a DESIGN constraint, that's a PHYSICAL constraint.  Whereas a lab may be able to fake it a produce a lens outside the documented power ranges on a conventional progressive, it is much harder to do so in FreeForm, particularly if the FreeForm software doesn't allow it.




> Maybe I should just give up on all of this absurdity and just deal with Hoya for all of my *Free-Form* digital processing, digital surfacing, customized, individualized, mesmerized progressives!


Maybe.  But I don't believe that any lens manufacturer can guarantee that all labs (company owned or independent) will correctly document the specs on their products.  Which was sort of my original point.  I'm not certain that documentation differences you pointed out are limited to FreeForm designs, as you asserted.  They could literally be mistaken information.  Or maybe the differences really are due to subtle differences in the production method at one lab vs another (i.e. which machinery they use, etc.).  Then it would be problematic, but not much more so than analogous lab differences in processing capability on conventional progressives.

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## optigrrl

> I even understand the basics (very basic) of free form surfacing, but I don't understand how the labs can change the so called minimum seg height and still expect the same results. Minimum is minimum. When you cut 4mm off the "minimum" seg height, something is lost. I think that would be common sense


That depends on the software in the design process. Awtech can adjust the corridor length by complex computations if you requested it - yes it would change the inherent optics of the design but he can do this. I believe that the Zeiss Individual is also able to let the dispenser order specific corridor lengths as well. This would allow a seg ht change from 18 to 14mm and achieve optimum add but it would also affect other parts of the design. 

So I guess what I am saying is: Yes and No. It would just depend on that patient's visual requirements and what they are willing to compensate for optically to get it. 

"Freeform digital surfacing" has allowed the doors to open up on the software side of the lens designs. The surfacing itself has benefits, finer curves, no warehousing of expensive laps, etc. but it's the design that ultimately dictates the wearer's comfort. No CNC generator is going to fix a bad lens design. A hard design is a hard design and a soft design is a soft design. Power management on 2 surfaces is going to be better than power management on only 1 surface. But the ability to manipulate a design to fit a patient's personal needs is what this is all leading to...complete customization. Complete lens surface optimization.

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## Fezz

> I'm not sure I completely follow you. Changing a seg height changes the FIT of a progressive, but not the design.


My point is, that I am assuming (maybe wrongly) that if the lab is stating a minimum seg height of lets say 14, but the company lists a minimum of 16, that the lab is entering the lower seg placement into the computer and then the lens gets made or designed with that parameter. I assume then that the design of the lens would be altered. I am not thinking of along the lines of them edging a prog at 15, but the minimum is 18 from the manufacturer. My thought is if they are entering a lower seg height into the program that essentially designs the lens, wouldn't that alter the design of the lens if the manufacturer is claiming a higher minimum height?

I am having trouble articulating my thought process. Thank you for clarifying.

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## HarryChiling

> The surfacing itself has benefits, finer curves, no warehousing of expensive laps, etc. ...... Power management on 2 surfaces is going to be better than power management on only 1 surface.


Finer Curves = Actually FF processing warps curves so the amount of warpage has to be factored into the design so the sum total of the desing + amount of anticipated warpage = intended lens design. That's where the limitations on curves and prism come in.

Expensive Laps = This benefits the lab and is of no consequence to the optics of the lens so the patient will not benefit from this unless their is a reduction in price for the lens.

Power Management on 2 surfaces better than 1 = Where did you hear that and can you provide facts to support that?  The reality is that the sum of the parts is what the patient views and actually splitting optics between two surfaces can increase the amount of complexity to the point where it is a detriment.  Some times keeping it simple is the way to go.  I would much rather a design with the progressive surfac on the back then a design with it split between two surfaces, for one the rays through a sperical or aspheric front surface are going to be more predictabel and more time can be spent optimizing the back surface then trying to make sure both surfaces work in unison.

I am waiting for a lab to come out and say we hired the Kebler Elves when they got laid off and that's why our lenses are better, I have a feeling that most opticians would buy that.

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## RT

> My thought is if they are entering a lower seg height into the program that essentially designs the lens, wouldn't that alter the design of the lens if the manufacturer is claiming a higher minimum height?


Ah.  Now I understand your point.  There could be a terminology gap here--Seg Height vs. Corridor Length.  If a lab is changing the Corridor Length, that would certainly produce a design difference.  If they are changing a Seg Height, that would produce a fit difference (or could cut off part of the reading area).  My previous comments were related to changing Seg Height--your original post was related to changing Corridor Length.  Although they are related, they are different.

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## Fezz

The labs are stating minimum seg heights...not corridor lengths! My original post was not about corridor lengths, it was about minimum seg heights.

See.....this is what I mean about the confusion!

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## optigrrl

> Finer Curves = Actually FF processing warps curves so the amount of warpage has to be factored into the design so the sum total of the desing + amount of anticipated warpage = intended lens design. That's where the limitations on curves and prism come in.
> 
> Expensive Laps = This benefits the lab and is of no consequence to the optics of the lens so the patient will not benefit from this unless their is a reduction in price for the lens.
> 
> Power Management on 2 surfaces better than 1 = Where did you hear that and can you provide facts to support that? The reality is that the sum of the parts is what the patient views and actually splitting optics between two surfaces can increase the amount of complexity to the point where it is a detriment. Some times keeping it simple is the way to go. I would much rather a design with the progressive surfac on the back then a design with it split between two surfaces, for one the rays through a sperical or aspheric front surface are going to be more predictabel and more time can be spent optimizing the back surface then trying to make sure both surfaces work in unison.
> 
> I am waiting for a lab to come out and say we hired the Kebler Elves when they got laid off and that's why our lenses are better, I have a feeling that most opticians would buy that.


Hopefully the technology will replace traditionally molded lenses and as more and more customized options become available these basic digitally surfaces lenses will move into a more affordable price category.

I attended a wonderful and informative seminar given by Mark Mattison-Shupnick who explained different categories of the freeform designs and expressed this process (optimum power management on dual surfaces) as being superior. Yes, it always breaks down to the math - GIGO. The algorythms have to be sound, the code for the software accurate and the equipment perfectly calibrated to make the two complex surfaces work as one. But why couldn't we expect that to better correct for aberration caused on one surface by managing  some of that aberration on the other surface?

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## Jubilee

Here is the explanation I have been given in the past for differing minimum seg heights.

Shamir states their piccolo has a min height of 16. However at 16 you have the FULL add and maximum reading width. Essilor states their Ellipse is min height 14, but only has around 85% of the add at that height and a limited reading area.

Many labs would look at this and state, "Well if it is good enough for Essilor, then it should be good enough for Shamir" and list the min height as being 14 or 15. Since even at this height, you had more of the add and reading power compared to the lens that advertises a 14mm height.

Of course, once that lab is bought by Essilor, it now changes and they insist on the 16 height rule, since we have so many other options now to choose from for lower heights...

I imagine that some of this happens with FF as well.

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## RT

> The labs are stating minimum seg heights...not corridor lengths! My original post was not about corridor lengths, it was about minimum seg heights.


Then if the labs are changing seg heights, they are not, in fact, changing the design.  That was one of your chief concerns.

As to why different labs have different minimum seg heights documented, I can't answer that.




> I attended a wonderful and informative seminar given by Mark Mattison-Shupnick who explained different categories of the freeform designs...


Mark's presentation and explanation on the subject is truly outstanding.  If you have a chance to hear him speak, I guarantee you'll become much better educated on the newer technologies.

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## HarryChiling

> Hopefully the technology will replace traditionally molded lenses and as more and more customized options become available these basic digitally surfaces lenses will move into a more affordable price category.
> 
> *I attended a wonderful and informative seminar given by Mark Mattison-Shupnick who explained different categories of the freeform designs and expressed this process (optimum power management on dual surfaces) as being superior.* Yes, it always breaks down to the math - GIGO. The algorythms have to be sound, the code for the software accurate and the equipment perfectly calibrated to make the two complex surfaces work as one. But why couldn't we expect that to better correct for aberration caused on one surface by managing some of that aberration on the other surface?


Then he's wrong and you just got GI'd and gave us GO.  The eye recieves the effects of the optical system that is placed in front of it, that is the additive effects of the front and the back surface, the back surface progressives are going to have the best advantages as the movment of the surface with the most comprimises (progressive surface) being on the back allows for less distortion and a wider field of view.

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## RT

> Then he's wrong...


That's sort of a harsh judgment of a presentation that you haven't even seen.

Your comments seem to assume that "dual surface" means a molded progressive on the front, and a toric or atoric surface on the back.  There are, however, several progressive designs that put part of the progressive on the front surface, and part on the back surface via FreeForm/digital surfacing.  There are, in fact, some advantages to such a design.

The presentation in question examines many progressive designs, including conventional, conventional + back surface atorics, back surface progressive, and dual surface progressives.  Mark does a fanstastic job of combining complex design properties with clear and understandable terminology.  As I said earlier, it is an outstanding and informative presentation, that you would benefit from if you had the luxury of attending.

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## Refractingoptician.com

Just curious , how many Free Forms have each of you sold ? 30 per month or more ?

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## Fezz

> Just curious , how many Free Forms have each of you sold ? 30 per month or more ?


None! I am still trying to figure what the heck they are, how they work, and how to demonstrate something that I can't grasp!


;):cheers::cheers::cheers::D

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## SailorEd

> _"How can we expect a patient to understand the technology when many of us do not understand it?"_


Just thought I'd throw this in since the word "free form" can encompass many different "types" of free form ...

http://www.eyecarebiz.com/article.aspx?article=102078

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## HarryChiling

> That's sort of a harsh judgment of a presentation that you haven't even seen.
> 
> Your comments seem to assume that "dual surface" means a molded progressive on the front, and a toric or atoric surface on the back. There are, however, several progressive designs that put part of the progressive on the front surface, and part on the back surface via FreeForm/digital surfacing. There are, in fact, some advantages to such a design.
> 
> The presentation in question examines many progressive designs, including conventional, conventional + back surface atorics, back surface progressive, and dual surface progressives. Mark does a fanstastic job of combining complex design properties with clear and understandable terminology. As I said earlier, it is an outstanding and informative presentation, that you would benefit from if you had the luxury of attending.


Yes it was kinda harsh and I love his presentations and he's a great person, but what I asked was:




> Where did you hear that and can you provide facts to support that?


The response I recieved was:




> I attended a wonderful and informative seminar given by Mark Mattison-Shupnick who explained different categories of the freeform designs and expressed this process (optimum power management on dual surfaces) as being superior.


So my statement was:




> Then he's wrong


and your response to it was:




> That's sort of a harsh judgment of a presentation that you haven't even seen..........There are, in fact, some advantages to such a design.


Maybe I'm missing something but this is the reason for some of the issues, no FACTS are being presented just because he said so doesn't make it a fact.  So now we haeva  predicament.  Either I'm wrong which won't be the first or last time, or he's just putting it in laymans term and not discussing the details.  BTW ther are small advantages to dual surfaces but I am under the assumption that they are negligable.

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## RT

> Originally Posted by *HarryChiling* 
> _Where did you hear that and can you provide facts to support that?_


What facts would you accept without cynically dismissing them as Marketing B.S.?  Optigrrl's response of where you could find an interesting presentation from someone who is not a lens manufactuer, seemed like a pretty good response.

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## HarryChiling

> What facts would you accept without cynically dismissing them as Marketing B.S.? Optigrrl's response of where you could find an interesting presentation from someone who is not a lens manufactuer, seemed like a pretty good response.


Any facts and I know who he is, you could even say he's listed on a progressive lens patent and that would hold more weight than just saying he's a lecturer or an ABO aproved apeaker or any of the number of other accolades the guy has racked up in his career which would be an impressive list.  It still doesn't make it a fact.  I just would like to read something peer reviewed, from a reputable journal, from a book.........etc.  Not just I heard it from so and so, if that's enough to pass as fact then some day someones gonna come along and say I heard from so and so that the keebler elves are making FF progressives.

If you could recommend a good book on progressives I'm all ears, a good article that discusses progressives and their various designs I'm all ears.

It's just ashamed that the products are being sold as the most technologically advanced according to so and so.

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## chip anderson

Give 'em hell Harry!

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## JRS

Throw in the towel Rick. 

Much like with politics and religion, the lines are already drawn in the sand. It's why I don't post anything I know about this (or other topics) here anymore - it all turns into a bashing ceremony about marketing, who likes what lens for various unknown reasons, or an Essilor is the evil empire rhetoric.

They can visit labs that produce free form, ask questions of the managers and staff that actually do the work, see real design data and equipment, or at the very least read many articles. Its not like there is no information out there or opportunities to get it.

See you at Expo I reckon.

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## HarryChiling

> Throw in the towel Rick. 
> 
> Much like with politics and religion, the lines are already drawn in the sand. It's why I don't post anything I know about this (or other topics) here anymore - it all turns into a bashing ceremony about marketing, who likes what lens for various unknown reasons, or… an Essilor is the evil empire rhetoric.
> 
> They can visit labs that produce “free form”, ask questions of the managers and staff that actually do the work, see real design data and equipment, or at the very least read many articles. It’s not like there is no information out there or opportunities to get it.
> 
> See you at Expo I reckon.


That's not fair, any attempt at trying to find a source of real info ends like this. You guys are breeding this not me.

Where does the JRS's, the RT's, and the Mark Mattison-Shupnick go to get their material when they write articles, posts, or marketing material? Oh and BTW there will be more thread slike this one that have the same unanswered question and they'll be posed by others not me. I think my question is valid, and by ignoring it the fire only burns hotter, one more person is going to ask, "where do I get concrete unbiased info on the subject".

And by the way screw what they say about Essilor still tops in my book.

I apoligize if the hard question have hurt anyones feelings, I find that many of the articles written have discrepencies in them and even questions to teh authors end with no answers. I am not saying the marketign is BS, I'm saying that the marketign came from somewhere supported by facts and I don't think it's as big of a deal as it's being made here to see that data. I get frustrated hearing the same old same old without any proof to back any of it up or any substance to back any of it up. Something as simple as, "how does using both surfaces to manage the power" brings this thread to halt and has you two throwing the towl in, I'm a big boy I understand may things and can figure out many things, I even managed to tie my shoes this morning all by myself.




> Regardless of the type of free-form lens, the placement of the actual progressive optics, whether on the front surface, back surface or split between both, has minimal impact on the magnitude of the inherent unwanted astigmatism of the design. Because a typical spectacle lens represents an “optical system” of fairly negligible thickness, the optics of each surface are essentially additive. Consequently, the inherent unwanted astigmatism of progressive lenses is not significantly influenced by placement of the progressive optics


There's one source that say's their no advanatges to using two surfaces.  Your turn.

----------


## AWTECH

The problems discussed are real.  I think they are the result of the lens manufacturers designs being processed by labs, that have various software.  There is software for lens designs, which is having to work with software made by another vendor to manage the lab.  Then these have to run machines with machine control software.  So you have three different software vendors supplying components and the lab has to assume that each is doing the job correctly.

Most software vendors only provide limited information as to how the code works with the other software.  So if there is a miscalculation from one to the other how will they know?

It is quite complicated and the various vendors each have there own agenda and most are not willing to provide an open approach.

Each lens manufacturer wants there designs to be able to be produced by multiple labs and there are different software used by different labs, different surfacing equipment, different polishing equipment, etc.

----------


## Fezz

The software and equipment differences must be very difficult to control. But, that alone, makes me question the whole process even more! How can we believe the claims of how accurate and precise the delivered end product is, if we can't even have universal standard to compare to?

----------


## Jacqui

That's another thing I've been saying recently. We need a standard to go by or everyone will be doing things their way and add to the confusion.

----------


## RT

> The software and equipment differences must be very difficult to control. But, that alone, makes me question the whole process even more! How can we believe the claims of how accurate and precise the delivered end product is, if we can't even have universal standard to compare to?


What universal standard do you use when you are checking a conventional front molded progressive?  How do you check claims of accuracy and precision other than checking power in the distance circle?




> That's another thing I've been saying recently. We need a standard to go by or everyone will be doing things their way and add to the confusion.


Feel free to contact The Vision Council about the upcoming standards meetings at VEE March 25-26, as they relate to digital surfacing.  JRS and I will both be there.

----------


## KStraker

> Maybe I should just give up on all of this absurdity and just deal with Hoya for all of my *Free-Form* digital processing, digital surfacing, customized, individualized, mesmerized progressives!


On the good side, Hoya gives you an rx verification card and the rx is not compensated. Also, I have not had any issues with base curve selection. The products work well and are delivered fairly quickly. The only down side is the premium price.

----------


## Robert Martellaro

> *http://www.2020mag.com/CE/TabViewTes...1/Default.aspx* 
> _Regardless of the type of free-form lens, the placement of the actual progressive optics, whether on the front surface, back surface or split between both, has minimal impact on the magnitude of the inherent unwanted astigmatism of the design. Because a typical spectacle lens represents an optical system of fairly negligible thickness, the optics of each surface are essentially additive. Consequently, the inherent unwanted astigmatism of progressive lenses is not significantly influenced by placement of the progressive optics_
> 
> There's one source that say's their no advanatges to using two surfaces. Your turn.


Darryl is not saying there is no advantage to working both surfaces, just that it has very little effect on the the maximum amount of _surface astigmatism_. 

Check out "Listing's Law" and how it's applied to the Hoya ID lens. 

http://www.freepatentsonline.com/EP1962127.html

----------


## chip anderson

If the "Vision Counsel" has any power why don't they standardise screws?
We don't need hundreds of differences in this industry.

Chip

----------


## AWTECH

> The software and equipment differences must be very difficult to control. But, that alone, makes me question the whole process even more! How can we believe the claims of how accurate and precise the delivered end product is, if we can't even have universal standard to compare to?


The differences in freeform are not much different than differences in traditional production.  Example: AR, look at the differences in AR production.  Then Essilor comes out with Crizal and has multiple labs producing good, (yet expensive AR), but they require very high quality standards.

Opticians typicall want the least expensive products-then they want the  best quality control standards

There is a cost to quality control.

----------


## Barry Santini

> On the good side, Hoya gives you an rx verification card and the rx is not compensated. Also, I have not had any issues with base curve selection. The products work well and are delivered fairly quickly. The only down side is the premium price.


Hoya's yet to be released newest lens, Hoya ID "MY Style", will have POW compensations.

FWIW

Barry

----------


## KStraker

> Hoya's yet to be released newest lens, Hoya ID "MY Style", will have POW compensations.
> 
> FWIW
> 
> Barry


They may have to invent a new price category to sell this one. If it's more than the current iD, I don't know how anyone can afford to wear it. I wonder if it will replace the current iD(not lifestyle iD), or if it will be in addition.

----------


## HarryChiling

> Darryl is not saying there is no advantage to working both surfaces, just that it has very little effect on the the maximum amount of _surface astigmatism_. 
> 
> Check out "Listing's Law" and how it's applied to the Hoya ID lens. 
> 
> http://www.freepatentsonline.com/EP1962127.html


Now that's interesting, so my understanding is that they use aspheric or atoric surfaces on both sides, with the additive effects of the differing aspheric coefficients creating the add power as well as minimizing the distortion by moving the most magnifying surface to the back of the lens.  It's also asymetrical in design and it looks like they are taking into consideration global variables for tilt.  So they are taking the horizontal and vertical magnification and splitting it 3/4 and 1/4 with the magnification set higher on the back surface for the horizontal to make the corridor wider and the magnification set higher along the vertical meridian on the front surface to reduce the amount of rotation of the eye to get to the reading.




> Moreover, it is possible to use a "bilaterally symmetrical semi-finished product" as an object side surface of the progressive-power lens and it is also possible to machine only the eyeball side surface after receiving an order into a bilaterally asymmetrical curved surface corresponding to a convergence action of an eye in nearsightedness, and a machining time and cost can be reduced.


From the patent, it's still a semi finished progressive split with it partially on the back.




> Also, a wide effective visual field with less distortion in wearing can be provided by reducing a magnification difference of an image between the distance portion and the near portion on the progressive-power lens.


It looks like the focus of the lens is on minimizing distortion.  It does not discuss any reductions or merits for marginal astigmatism.  This lens seems to focus on being more orthogonal in design.  This could be a good lens design for say and engineer or someone that requires minimized distortion, their will be more blur though so it might be problematic for a hyperope for example.

It would be awesome if I had a design name to go with that patent and maybe the same for other lens designs.  This could help opticians to better fit the design to the patients.  Thanks Robert.

----------


## HarryChiling

Using the same philosopy from the previous patent couldn't a lab use a traditional design from any manufacturer and use a lower base curve than requred to minimize magnification and then use an atoric surface ground onto the back surface to clean up the off base design or even use a lower add blank then use an atoric coefficient on the back side to increase the add along the vertical meridian as well. This methodolgy can be potentially used with many of the current designs available, correct?

Also I forgot to mention in the above post the effects of magnification are only going to be realized only if the lens has some substance to it (ie thickness).  So a minus lens in the NVP or a plus lens in the DVP.

----------


## Fezz

> The differences in freeform are not much different than differences in traditional production.  Example: AR, look at the differences in AR production.  Then Essilor comes out with Crizal and has multiple labs producing good, (yet expensive AR), but they require very high quality standards.
> 
> Opticians typicall want the least expensive products-then they want the  best quality control standards
> 
> There is a cost to quality control.


I like the Crizal analogy. 

I often wonder why I can see differences in the residual color of Crizal AR coats, when I assumed that the procedure was standardized and strictly followed.

Do you see any type of standardization ever happening with the digital surfacing and the lenses that are being produced? As a lab with the digital processing and the manufacturing ability for these lenses, what are your biggest challenges when dealing with *US*-the dispensers of such products?

----------


## HarryChiling

> I like the Crizal analogy. 
> 
> I often wonder why I can see differences in the residual color of Crizal AR coats, when I assumed that the procedure was standardized and strictly followed.
> 
> Do you see any type of standardization ever happening with the digital surfacing and the lenses that are being produced? As a lab with the digital processing and the manufacturing ability for these lenses, what are your biggest challenges when dealing with *US*-the dispensers of such products?


Their is a communications standard in place now through the VCA if everybody is following it or not is another story, and is it robust enough to handle the current state of the technology is another question I am sure will be assesed in NY.

I get the feeling that the dealing with dispensers is tricky in the sense they don't want to give away too much, for fear of alienateing or keeping the magic perpetuated I don't know, but that's the feelign I get for what it's worth.

----------


## Robert Martellaro

> From the patent, it's still a semi finished progressive split with it partially on the back.


That's the Lifestyle (in the US). The ID is surfaced (aspheric/atoric) on both sides.




> It looks like the focus of the lens is on minimizing distortion. It does not discuss any reductions or merits for marginal astigmatism. This lens seems to focus on being more orthogonal in design. This could be a good lens design for say and engineer or someone that requires minimized distortion, their will be more blur though so it might be problematic for a hyperope for example.


To the best of my knowledge, the ID is optimized for inset (PD and Power- a zero inset is possible) and near vision distance only. The software determines the base curve (ID only), which should result in very little power and astigmatic error off-axis, at least for typical positions of wear. 




> Thanks Robert.


Your welcome. Here's a hint on patent searches- use "progressive power lens" instead of "progressive addition lens".

----------


## HarryChiling

> Your welcome. Here's a hint on patent searches- use "progressive power lens" instead of "progressive addition lens"................................The software determines the base curve (ID only), which should result in very little power and astigmatic error off-axis, at least for typical positions of wear.


Thanks, how did you know it was the lifestyle or the ID? I have a few patents for a few designs already but not many of them have branding information in the patent.

But a progressive is created by introduceing tangetial error to the degree of the add of axis, that's what makes it a progressive so chosing the correct base means nothing if the aspheric coefficient is wrong.  For instance a plano falls on a 6 base, what we don't say is that a plano falls on a spherical 6 base which has a coefficient of 1 but what if that 6 base had a coefficient of 5.0 that would not be the best base with that particular coefficient, so the base would need to be altered to match the coefficient or the coefficient would need to be changed to match the base, this patent seems to imply the coefficient is choosen to create the add power combined with the back surface coefficient.  Their is a comprimise believe me when I tell you their must be a comprimise somewhere.

----------


## AWTECH

> I like the Crizal analogy. 
> 
> I often wonder why I can see differences in the residual color of Crizal AR coats, when I assumed that the procedure was standardized and strictly followed.
> 
> Do you see any type of standardization ever happening with the digital surfacing and the lenses that are being produced? As a lab with the digital processing and the manufacturing ability for these lenses, what are your biggest challenges when dealing with *US*-the dispensers of such products?


I think the biggest challenge is understanding the knowledge and capabilities of each freeform producer. Like any work, the more standard it is the easier it is.

Unfortunately the VCA standards, which are helpful do not address all of the issues to make for excellent communication.

As an example: Assume two labs use the same lab management software and the same lens design software, but they each have different generators. If one generator is set to different calibration standards, or one machine uses a different size diamond finish tool, you may get different results. 

The lab also has to typically polish the lens after generation. What polishing standards are used? What polishing tools or technique is used.

My point is just like regular surfaced jobs good quality control leads to good quality. The lens company can only ultimately control the lenses they produce in there own facilities. 

At ICE-TECH we actually control our complete process, but as some of you know we did not always get every job right. And here on Optiboard naturally we got the opportunity to try the extreme limits with jobs sent by Optiboarders. This was actually very helpful, in testing our limits. And still today there are many freeform jobs we can produce that no other freeform facility can produce.

----------


## Fezz

Awtech,

So.......is it safe to say that a Seiko Supercede(or Autograph II, or Indo, etc) lens may end up being a different design from lab#1, then it is from lab#2, and both different from lab#3?

If so............................should we all sill drink the Kool-Aid and assume that these lenses are all the same?

For those that my bring up the traditional surfacing statement and how it isn't any different scenario, I will assume that a 6BC Sola XL is the same *design* no matter what lab surfaces it. A Hoya Wide starts out the same design regardless of where it is surfaced, or is it different?

----------


## HarryChiling

> For those that my bring up the traditional surfacing statement and how it isn't any different scenario, I will assume that a 6BC Sola XL is the same *design* no matter what lab surfaces it. A Hoya Wide starts out the same design regardless of where it is surfaced, or is it different?


But ANSI allows up to 1 diopter distortion so it may matter if the lens is a first run blank or the last run out of the mold, I think that analogy would apply here.  So what si the creme de creme of generators, polishers, and overall systems?  That's gonna be even more opinionated then which progressive is better, Fezz I think this is a lesson in tail chasing.  It's gonna all boil down to do your trust your lab and their people.  Do you trust the design?

I just would like to know when the design is appropriate?

----------


## AWTECH

Deleted due to duplication. (see below)

----------


## AWTECH

> Awtech,
> 
> So.......is it safe to say that a Seiko Supercede(or Autograph II, or Indo, etc) lens may end up being a different design from lab#1, then it is from lab#2, and both different from lab#3?
> 
> If so............................should we all sill drink the Kool-Aid and assume that these lenses are all the same?
> 
> For those that my bring up the traditional surfacing statement and how it isn't any different scenario, I will assume that a 6BC Sola XL is the same *design* no matter what lab surfaces it. A Hoya Wide starts out the same design regardless of where it is surfaced, or is it different?


NO it is not a different design but thickness surface control maybe different from lab to lab, but in general I think these designs are now to the point for normal, within there paramaters, jobs being very close to the same from one to another as far as the product goes. 

Then there is the marketing: Min. fitting height for example

These can be whatever the manufacturer or the lab says, and hopefully they will be correct.

----------


## Fezz

> NO it is not a different design but thickness surface control maybe different from lab to lab, but in general I think these designs are now to the point for normal, within there paramaters, jobs being very close to the same from one to another as far as the product goes. 
> 
> Then there is the marketing:  Min. fitting height for example
> 
> These


But.....that brings me back to the original post and the confusion. If marketing says one thing, but it is general knowledge that it is something else....I get it!

But, when I have an OWNER of a dedicated digital surfacing lab{who I get diverted to when I have a *technical* question}, tell me that:

I just spoke with one owner of one of the labs. *He clearly stated that they alter seg heights "All day long"!* I asked to explain then why he couldn't alter the prism. His response was that "The computer won't let us."!

Is that a marketing issue? Is it a technical issue. Is it a reality?

----------


## AWTECH

> But.....that brings me back to the original post and the confusion. If marketing says one thing, but it is general knowledge that it is something else....I get it!
> 
> But, when I have an OWNER of a dedicated digital surfacing lab{who I get diverted to when I have a *technical* question}, tell me that:
> 
> I just spoke with one owner of one of the labs. *He clearly stated that they alter seg heights "All day long"!* I asked to explain then why he couldn't alter the prism. His response was that "The computer won't let us."!
> 
> Is that a marketing issue? Is it a technical issue. Is it a reality?


 Without knowing the specifics of the lens calculation software, I assume they can not alter the prism, since the lab management software, and/or the lens design program will not allow it.  As far as seg height I assume this has a software funtion in the lens design program that give choices.  Then on top of the choices, how much full read power do you really need.  If I advertise a short fitting height of say 15mm and to achive this I know I can get it in a certain frame with the max lower B measurement right at the center of the add, then I only need one little spot to be the full add power to be OK with the advertising.  However, the advertising will not let this short fitting height work in all frames, but in most it would be OK.

The problem is that when one company has a good fitting height that works on all frames of 17mm min. then for some frames another competitor says they can fit to 16mm, well to be competitive the first company will often then advertise new 16mm fitting height with not real lens design change.  But for 80% of the frames both designs may work great at 16mm and another 15% are OK with 5% having not full reading power.

I hope this explains your question about prism vs. seg height.

----------


## MarcE

> I just spoke with one owner of one of the labs. *He clearly stated that they alter seg heights "All day long"!* I asked to explain then why he couldn't alter the prism. His response was that "The computer won't let us."!
> 
> Is that a marketing issue? Is it a technical issue. Is it a reality?


The seg height can be chopped of in the edger.  The FF generator won't stop you there.

If you wore progresives, you would know what I do.  The FF designs just work better.  You don't have to explain it to the patient.  They don't care and wouldn't understand it anyway.

Just say it like this:  "Our best no-line multifocal design is $xxx, which comes complete with the super-slick, easy to clean anti-reflection treatment".

If it's too expensive, you sell you normal lens.  

If they pay for it, order the FF lens and after 6 pairs you will have your proof (If you pick the right designs)

----------


## AWTECH

> The seg height can be chopped of in the edger. The FF generator won't stop you there.
> 
> If you wore progresives, you would know what I do. The FF designs just work better. You don't have to explain it to the patient. They don't care and wouldn't understand it anyway.
> 
> Just say it like this: "Our best no-line multifocal design is $xxx, which comes complete with the super-slick, easy to clean anti-reflection treatment".
> 
> If it's too expensive, you sell you normal lens. 
> 
> If they pay for it, order the FF lens and after 6 pairs you will have your proof (If you pick the right designs)


Your comments are well stated and simple to understand.  Unfortunately the desire for knowledge creates many of the misunderstanding with freeform designs.

----------


## GAgal

> Without knowing the specifics of the lens calculation software, I assume they can not alter the prism, since the lab management software, and/or the lens design program will not allow it. As far as seg height I assume this has a software funtion in the lens design program that give choices. Then on top of the choices, how much full read power do you really need. If I advertise a short fitting height of say 15mm and to achive this I know I can get it in a certain frame with the max lower B measurement right at the center of the add, then I only need one little spot to be the full add power to be OK with the advertising. However, the advertising will not let this short fitting height work in all frames, but in most it would be OK.
> 
> The problem is that when one company has a good fitting height that works on all frames of 17mm min. then for some frames another competitor says they can fit to 16mm, well to be competitive the first company will often then advertise new 16mm fitting height with not real lens design change. But for 80% of the frames both designs may work great at 16mm and another 15% are OK with 5% having not full reading power.
> 
> I hope this explains your question about prism vs. seg height.


Thank You, that actually helps me understand a lot more.

----------


## xiaowei

> Regardless of the type of free-form lens, the placement of the actual progressive optics, whether on the front surface, back surface or split between both, has minimal impact on the magnitude of the inherent unwanted astigmatism of the design. Because a typical spectacle lens represents an “optical system” of fairly negligible thickness, the optics of each surface are essentially additive. Consequently, the inherent unwanted astigmatism of progressive lenses is not significantly influenced by placement of the progressive optics


WOW, what a thread, but this statement expresses exactly what I was considering to say already a long time ago, but did not dare....

If you work in complex THICK optics with MANY lenses (up to 15 and more), a single eyeglass is such a THIN system, so that discussions about the relative benefit of putting something on the front or the back are really only marketing hype. Also consider the often-mentioned "keyhole effect", as long as the patient is not wearing "glass bricks", which are becoming more and more out of fashion with high n lenses, the typical distance from cornea or better (what would be effective) pupil to the back surface of the eyeglass is typically much LARGER than the thickness of the eyeglass itself, hence it really is a THIN system. It will make differences in the order of some subwaves or a few waves OPD (aberrations), if you simply move the surface data over without change (and our company usually is in subwaves, i.e. better than "diffraction limited" performance), but it´s nothing that could be optimized away by fine-tuning the respective other surface, at least at the advent of free-from.

(Also regardíng the "Listing Law" or "Advanced procedures" as "Eye-Point Technology" - even if I personally really like Shamir!)

IMHO it´s all marketing, also typically contents of most patents today will not really stand scientitic scrutinity, the real details are NOT given, but some silly differences and generalizations are claimed to make it difficult for competitors to come up with a similar product. That´s unfortunatelly the truth IMHO, even I myself hold such a silly patent, because the company wanted it.
:angry:

Sorry the harsh tone, at least if it appears so...

:cheers:

XW

----------


## shanbaum

> Unfortunately the VCA standards, which are helpful do not address all of the issues to make for excellent communication.


Allen, those of us who have worked rather hard to produce this standard would really appreciate it if you would show up at our meetings and tell us where we're falling short.  Or, just give one of us a call.  We'll be happy to answer any questions.




> As an example: Assume two labs use the same lab management software and the same lens design software, but they each have different generators. If one generator is set to different calibration standards, or one machine uses a different size diamond finish tool, you may get different results.


In fact the current release of the DCS provides a means by which lens design software can produce different surface definition files for different machines (so, you don't need to show up to cover that one).  

Some machine vendors see it as their responsibility to produce the surface described in the SDF.  Others are happy to have some help from the LDS (lens design software) suppliers.  The standard supports either approach.

And, I would add, finished products on which the surface deviates from the surface described in the SDF are nonconforming.

----------


## Robert Martellaro

> (Also regardíng the "Listing Law" or "Advanced procedures" as "Eye-Point Technology" - even if I personally really like Shamir!)
> 
> IMHO it´s all marketing, also typically contents of most patents today will not really stand scientitic scrutinity, the real details are NOT given, but some silly differences and generalizations are claimed to make it difficult for competitors to come up with a similar product. That´s unfortunatelly the truth IMHO, even I myself hold such a silly patent, because the company wanted it.
> :angry:
> 
> Sorry the harsh tone, at least if it appears so...
> 
> :cheers:
> 
> XW


 
Some of these "enhancements" (except for power error and marginal astigmatism) when examined individually, are probably clinically insignificant, and may only provide a way for the manufacturer to differentiate their products in the marketplace. If I believe that the enhancements are done in a way that drives up the price of the lens for the sole purpose of exclusivity, I'll just steer my clients toward a lens design that provides the same level of performance for less cost.

It's difficult to determine how effective these enhancements are to the individual wearer, especially when dealing with the quality of vision instead of the quantity of vision. I suspect that placing the PAL on the back _and_ making the optics Listing's Law compliant, or any reduction in skew distortion combined with slight field of view increase may have a cumulative, or synergetic effect, or at a minimum, crosses the threshold of perceptibility. If true, it might make this type of lens desirable for those emerging presbyopes, or when the Add power changes significantly. 

My brain desires a lens that _feels_ comfortable, and provides the quantity of vision at the far and near point that comes closest to what the most refined refraction can provide. For multifocal lenses, that may require complex surfaces and software that compensates for position of wear and the specific Rx. I can assure you that Shamir's "Eye-Point Technology" combined with free-form generation is not marketing hype- similar software used by Zeiss, Rodenstock, and other companies is capable of providing clearer off-axis vision in the stronger and more complex RXs.

Believe me, I share your skepticism, especially for wild-eyed claims for minute performance improvements. OTOH, this is a blend of vision and optical science- where one might say that "one eye sees, the other feels".

----------


## Barry Santini

> My brain desires a lens that _feels_ comfortable, and provides the quantity of vision at the far and near point that comes closest to what the most refined refraction can provide. OTOH, this is a blend of vision and optical science- where one might say that "one eye sees, the other feels".


Ah yes, Robert. You've stated what I preach: There's a _brain_ behind every evaluation. And every evaluation is a _comparative_ against previous visual experience. Although we know what the numbers mean and can forecast _optically_, what we cannot know is just how an _individual_ will react to a given lens design/Rx. So, statistically, we look at the _overall_ satisfaction and feedback from our clients.

This, then, is the main reason I will continue to vet out the best lens technology I can find, and recommend it to my clients. I am committed to this, and they expect no less (just like others here).

People like "us" are the only future of eyewear/opticianry. The _basement_ is already targeted to be eliminated by refractive technology.

IMHO & FWIW

Barry

----------


## SailorEd

> Just say it like this: "Our best no-line multifocal design is $xxx, which comes complete with the super-slick, easy to clean anti-reflection treatment".


I go a step further and show them a simple diagram on how free form lenses help alleviate coma aberration.  People "get" "less blurriness" and they jump at it.  We make follow up calls to all our patients who get glasses and to a person, each one who has purchased our free form lens is very satisfied (some even say they "love it").  Pretty good indication they are coming back and will stay with the free form design.  AND, a good indication that if they go somewhere else and get a "less expensive" (read: inferior) lens, they won't be happy with it and will ultimately return to us. 

The only lenses we offer here is the Varilux Ellipse and Physio both regular and 360 and the only AR we offer with these is the Avance'.  Excellent results with both.

----------


## chip anderson

SailorEd:

You do realize that you are admitting to selling lenses with "blurriness." The ultimate way to eliminate this "blurriness" would be a translating bifocal or trifocal. Why not carry it all the way and convert these people to translating bifocals? 
By your statement here, it's what they would be happiest with.
Your statement seems to say:  Our lenses have abberation but less of it.  

Chip

----------


## SailorEd

> SailorEd:
> 
> You do realize that you are admitting to selling lenses with "blurriness." 
> By your statement here, it's what they would be happiest with.
> Your statement seems to say: Our lenses have abberation but less of it. 
> 
> Chip


Yes, I do realize that I am selling lenses with blurriness in them.  First time wearers need to be told this ... and those who already wear progressives, they already know it.  My main "thrust" is to educate the patient - to tell them the good and the not so good about the lens I am recommending to them.  I show them a simple diagram of how a progressive is designed and explain to them that there is going to be some blurriness if one moves their eyes to the edge of the lens and I explain the benefits and limitations of a progressive before they buy it.  

Now, to tell them that a new lens on the market (Physio 360 or the like) has less blurriness and then to show them in a simple diagram why (coma aberration) ... well, they "get" it and I am finding about 75% of the time decide to go with it.  I had a lawyer come in and I do something that I very rarely do ... I actually "hard sold" him on the 360.  He came back with his wife to pick up his glasses and sat down and said, "Ok, so you have glasses that will allow me to see through walls, huh?" I smiled and then put them on and adjusted them.  He was absolutely impressed ... the clarity was excellent and he was still talking to his wife about them as he went out the door.  I made him promise he'd tell everyone at the law firm about them.  (smile).

So, yeh, I'm "right up front" with our patients ... and they appreciate it.  And so, with this economy ... I'm saying "What recession?"  Our sales remain strong and our patient base keeps expanding.

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## HarryChiling

> Yes, I do realize that I am selling lenses with blurriness in them. First time wearers need to be told this ... and those who already wear progressives, they already know it. My main "thrust" is to educate the patient - to tell them the good and the not so good about the lens I am recommending to them. I show them a simple diagram of how a progressive is designed and explain to them that there is going to be some blurriness if one moves their eyes to the edge of the lens and I explain the benefits and limitations of a progressive before they buy it. 
> 
> Now, to tell them that a new lens on the market (Physio 360 or the like) has less blurriness and then to show them in a simple diagram why (coma aberration) ... well, they "get" it and I am finding about 75% of the time decide to go with it. I had a lawyer come in and I do something that I very rarely do ... I actually "hard sold" him on the 360. He came back with his wife to pick up his glasses and sat down and said, "Ok, so you have glasses that will allow me to see through walls, huh?" I smiled and then put them on and adjusted them. He was absolutely impressed ... the clarity was excellent and he was still talking to his wife about them as he went out the door. I made him promise he'd tell everyone at the law firm about them. (smile).
> 
> So, yeh, I'm "right up front" with our patients ... and they appreciate it. And so, with this economy ... I'm saying "What recession?" Our sales remain strong and our patient base keeps expanding.


Please stop saying coma aberration.

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## Uncle Fester

> Please stop saying coma aberration.


I'll bite--My newest favorite optical lingo to throw at the engineer or anyone else who I want to distract from looking at the man behind the curtain;)  is to refer to Seidel Aberrations. One of which is "coma". So is this incorrect because coma is an aberration? Would it be correct to say "the aberration coma"?

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## HarryChiling

> I'll bite--My newest favorite optical lingo to throw at the engineer or anyone else who I want to distract from looking at the man behind the curtain;) is to refer to Seidel Aberrations. One of which is "coma". So is this incorrect because coma is an aberration? Would it be correct to say "the aberration coma"?


Because spherical aberration and coma are both aberrations that would be problematic in wide aperature systems, the eye has a pupil that limits the area of the lens that is used so these are the least problemtic aberrations to worry about from a spectacle desingers point of view. It sounds great to talk about sphercal aberration and coma, but they don't mean anything in spectacle lens design if you had to sacrifice somewhere I would rather a lens with more coma and sph aberration than oblque astigmatism, distortion (in it's true sense), curvature of field, or even chromatic aberration probably in that order as well.

You want to reduce coma in the corridor order a Natural long corridor means less disfference in power from the top of aperature to the bottom of the aperature.  You want to redue coma hav the patient instill miotics or go out in full on sun without any filters to their lenses.  If a lens is sold to you because it reduces coma then you've been had IMO.

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## Uncle Fester

> Because spherical aberration and coma are both aberrations that would be problematic in wide aperature systems, the eye has a pupil that limits the area of the lens that is used so these are the least problemtic aberrations to worry about from a spectacle desingers point of view. It sounds great to talk about sphercal aberration and coma, but they don't mean anything in spectacle lens design if you had to sacrifice somewhere I would rather a lens with more coma and sph aberration than oblque astigmatism, distortion (in it's true sense), curvature of field, or even chromatic aberration probably in that order as well.
> 
> You want to reduce coma in the corridor order a Natural long corridor means less disfference in power from the top of aperature to the bottom of the aperature.  You want to redue coma hav the patient instill miotics or go out in full on sun without any filters to their lenses.  If a lens is sold to you because it reduces coma then you've been had IMO.


[Genuflecting Optician]:cheers:

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## chip anderson

One must remember that although the pupil may be from one to 8 mmm the patient is seeing through (siimultainiously) much more of the lens, even in a contact lens the amount of lens being used is larger than the pupil (let's leave out selective brain interaction with multifocals here).

If this were not true what one view at far distances would be no larger than pupil diameter.

Chip

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## DragonLensmanWV

> [Genuflecting Optician]:cheers:


This works:

*
*

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## HarryChiling

> One must remember that although the pupil may be from one to 8 mmm the patient is seeing through (siimultainiously) much more of the lens, even in a contact lens the amount of lens being used is larger than the pupil (let's leave out selective brain interaction with multifocals here).
> 
> If this were not true what one view at far distances would be no larger than pupil diameter.
> 
> Chip


Your right, but sph abb and coma are dependent on the pupil size.  Also although you may view an entire room only the macula is capable of BCVA while the remainder of the room will fall on other parts of the eye, that means if you were to use eccentric viewing techniques depending on how eccentric your view the VA is gauranteed to be less than 20/20.  

Basically to bring something into focus you must look directly at it.

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## Comma

To all spherical aberration and coma lovers :
Do this little exercice just for fun :
Stare any letter on the 20/20 line, then, still staring at this letter, try to read any letters that are more then 4 inches away on the same line, BUT KEEP staring at your first letter.  You won't be able to read them at all.
Want to go further ? Place something around 3mm over your glasses to cover that same letter and try to read the other letters. You won't be able.

My conclusion : we really read and have real crisp vision in about a 3mm diameter at any time in any lens. 1.5 mm (side to side, up and down) from that exact point of the lens we are looking at.  Spherical aberrations at 1.5 mm ? You have to have a quite strong RX ! Mr Prentice is my friend...

You won't even notice these aberrations in real life because our vision is far from being perfect surrounding that little 3mm area of our lenses.
I did the same with CL : a 1mm round object places directly on the lens did about the same thing. 0.5 mm causing spherical aberrations ?

I think spherical aberrations and coma are mostly pointless in real life

Now, do your own conclusions...
Or maybe I'm wrong ?

Please forgive my quite unperfect English writing :o

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## stellarindia01

I just find it amazing that something as simple as consistent minimum seg heights can not be found! How are we supposed to believe that the actual lens designs will be consistent?
Lisa11

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## SailorEd

> Please stop saying coma aberration.


Well, you see, I can't stop saying it because the significant reduction in coma aberration is one of the major advances in free from technology. Yeah, some other aberrations in lens design would be nice, but, since we're talking about existing free-form technology and since I was talking specifically about Varilux Physio 360, then I have to talk about just what that lens does for my patients. i. e. 

"• Varilux Physio. Even the best progressive eyeglass lenses distort light waves as they pass through the peripheral optics of these lenses, reducing visual quality. The Varilux Physio and Physio 360 are progressive designs that minimize many of these distortions in the lens, *particularly coma*, by applying a technology known as Wavefront Advanced Vision Enhancement (WAVE) to identify and compensate for aberration deformities by controlling the quality of the wavefront that passes through the eyeglass lens. The result, according to Essilor, is a progressive lens with enhanced central and peripheral vision, a 30% wider corridor, greater coma control, and more contrast and greater acuity in all fields of vision"

And, well, what does this mean to my patients?

As much as 30 percent increase in contrast sensitivity resulting in a more accurate duplication of the visual performance achieved during the eye exam (much smaller lenses used in that room, hence, less coma aberration).The benefit of First Time Ever control of the Coma aberration , allowing for sharper distance and improved night vision that is Superior to all other lenses.An optimized edge-to-edge performance that goes beyond the perepheral limits of traditional lenses. Now, granted, these are "selling points" but the patient understands them when I explain them in the context of "coma aberration" and when I explain just what we mean by that in a simplified diagram.

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## optical24/7

Physio's and the Ellipse ( even the 360's ) are not Free Form lenses. The regular versions are traditional Semi-finish, surfaced on the back conventionally.

360's are the same exact lenses, only digitally surfaced on the back side. 

The closest lens Varilux has to free form is their Ipsio, and it's not totally free form. It's got a pre-cast progressive front surface.

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## SailorEd

> Physio's and the Ellipse ( even the 360's ) are not Free Form lenses. The regular versions are traditional Semi-finish, surfaced on the back conventionally.
> 
> 360's are the same exact lenses, only digitally surfaced on the back side. 
> 
> The closest lens Varilux has to free form is their Ipsio, and it's not totally free form. It's got a pre-cast progressive front surface.


There can be a million and a half definitions of what makes or what does not make a free form lens.  Actually there are no free form lenses, there are only lenses that are manufactured using free form technology.  

In the case of the Physio and Ellipse regular and "360", while the regular Physio and Ellipse are spherical in design on the front surface and then surfaced regularly on the back, the Physio 360 and Ellipse 360 are Digitally molded on the front surface and digitally surfaced on the back.  
http://thelensguru.com/digitalChart.php

Hey, bottom line ... they are a much better lens and I have had a very good reaction from my patients ... that being said ... whether they meet the "true" nature of free form or not, i.e. extra measurements involving eye and head movements and a lot of extra equipment ... I'll stick with them for now because of their superior performance.

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## HarryChiling

> The result, *according to Essilor*, is a progressive lens with enhanced central and peripheral vision, a 30% wider corridor, greater coma control, and more contrast and greater acuity in all fields of vision"


Thank you, I have seen the light. Remember this thread is about confusion with FF progressives and i believe that companies are dropping the ball by not educateing the psuedo professionals that are selling their products.  With that said the lens may still be a good lens, but coma is not a significant aberration so I wouldn't choose a design based on reduction of coma alone.

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## HarryChiling

> In the case of the Physio and Ellipse regular and "360", while the regular Physio and Ellipse are spherical in design on the front surface and then surfaced regularly on the back, the Physio 360 and Ellipse 360 are Digitally molded on the front surface and digitally surfaced on the back. 
> http://thelensguru.com/digitalChart.php


Most manufacturers are starting to digitally mold their lenses nowadays so the traditionel ellipse and the traditional physio are digitally molded either way the 360 just refers to the technology used on the back surface.

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## optical24/7

> Most manufacturers are starting to digitally mold their lenses nowadays so the traditionel ellipse and the traditional physio are digitally molded either way the 360 just refers to the technology used on the back surface.


 
Exactly. There are absolutely no differences on the front surface of  traditional Physio and Ellipes compared to the 360 series. That's also why there are no difference in the laser ingraving between the 2 . (regular and 360 series.)

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## HarryChiling

You know these kind of conversations will continue to go on untill their are some sort of metrics set in place. The accepted norm for corridor width and marginal astigmatism is 1.00D or the sph equiv of 0.50D, if a company were to say our corridor is 13mm wide in the intermediate, then this would provide a great deal of information for the fitter. The threshold for TCA is 0.1. The problem with the metrics is gonna be the die hard fitters of a certain design that right now focus on the wider corridor are going to see that their are sacrifices in other areas of the desing which is acceptable, but it would allow fitters to better fit their patients need with the correct design. Not that's a customized fitting and it can be done with even traditional desings.

FF is a great technology and has it's rightfull place at the top of the food chain in PALs but given how little we know and I mean we as me and everyone else included it leaves much to be desired.

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## Barry Santini

By the way (and Harry-Darryl, correct me if I'm wrong here):

Spherical aberration is an *on-axis* aberration

Conceptually, Coma is spherical aberration's *off-axis* first cousin.

Barry

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## HarryChiling

> By the way (and Harry-Darryl, correct me if I'm wrong here):
> 
> Spherical aberration is an *on-axis* aberration
> 
> Conceptually, Coma is spherical aberration's *off-axis* first cousin.
> 
> Barry


 
That's a good definition.

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## chip anderson

At first this may seem like a duplicate post but..
Could not "free-form" be used for these specialty needs?  It seems this would be thier greatest potential
If a patient comes in with a "standard Rx" and desires:
a: Glasses to focus shorter to say, fix watches.
b: Glasses to view a particular work station at an unusual close distance such as an overhead display or something at 8' and 6'6" high.
c: An artist that wants to view an easel with offset prism/add but be out of the way for distance in the opposite direction.
d: A painter or mechanic that needs to see overhead at a distance different from his near/distance range.
e: Piano organ player with special distance/ intermediate/ near ranges to see the music, keyboard/ director.

Are these technically within the possiblities  for current "free form" _technology?_

Chip( Neo-optician)

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## Jacqui

All should be possible with current technology.

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## Lazarus

> Awtech,
> 
> So.......is it safe to say that a Seiko Supercede(or Autograph II, or Indo, etc) lens may end up being a different design from lab#1, then it is from lab#2, and both different from lab#3?
> 
> If so............................should we all sill drink the Kool-Aid and assume that these lenses are all the same?
> 
> For those that my bring up the traditional surfacing statement and how it isn't any different scenario, I will assume that a 6BC Sola XL is the same *design* no matter what lab surfaces it. A Hoya Wide starts out the same design regardless of where it is surfaced, or is it different?


Fezz,
You raise great questions. I'll blow your mind even further. I ordered three digital progs(i probably shouldnt mention which brand) from three different labs. They are considered the top digital prog labs. 2 on east coast and one in mid-west. I ordered the exact same rx, same lens , same measurements and provided same exact frame tracing. They send you a sheet with the verified rx that we should check. They should be the same right?????? Well they werent. All 3 labs provided different verified specs. Why? How do I know which of the 3 are the best for the patient? Is there no standard? Conduct that test yourself and see what you get. All three labs are provided with special software from the same manufacturer. But they also have there own lab software system which i guess works with the lens manufacturer software. My guess is when you mix the lab software with the lens company software its causing a different result?? So now the question becomes which is right? They all cant be right or can they? Are we to accept blindly what is on the piece of paper? Would love to hear feedback

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## Jacqui

> Fezz,
> You raise great questions. I'll blow your mind even further. I ordered three digital progs(i probably shouldnt mention which brand) from three different labs. They are considered the top digital prog labs. 2 on east coast and one in mid-west. I ordered the exact same rx, same lens , same measurements and provided same exact frame tracing. They send you a sheet with the verified rx that we should check. They should be the same right?????? Well they werent. All 3 labs provided different verified specs. Why? How do I know which of the 3 are the best for the patient? Is there no standard? Conduct that test yourself and see what you get. All three labs are provided with special software from the same manufacturer. But they also have there own lab software system which i guess works with the lens manufacturer software. My guess is when you mix the lab software with the lens company software its causing a different result?? So now the question becomes which is right? They all cant be right or can they? Are we to accept blindly what is on the piece of paper? Would love to hear feedback


Been trying to say that for some time now and no one listens.  :cry:   :cry:  Not only are there software differences, but also equipment to take into consideration.

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## HarryChiling

> Been trying to say that for some time now and no one listens.   Not only are there software differences, but also equipment to take into consideration.


Jacqui,

I've been right one board with you. I even made a suggestion for the company of the software to provide decompensation software to opticians so that they can verify that the Rx is correct according to their specs. To many variables and who's to say that the end result was what the designer's software intended when the job ultimately gets delivered.

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## Jacqui

> Jacqui,
> 
> I've been right one board with you. I even made a suggestion for the company of the software to provide decompensation software to opticians so that they can verify that the Rx is correct according to their specs. To many variables and who's to say that the end result was what the designer's software intended when the job ultimately gets delivered.


We need some way using conventional equipment to verify these. Not all of us (even freeform labs) can afford Rotlex FFV units to check these lenses.

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## chip anderson

Are Rotflex gadgets accurate?  If they can't be checked with a lens bench or something how would one know they were calibrated accurately?

chip

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## HarryChiling

> We need some way using conventional equipment to verify these. Not all of us (even freeform labs) can afford Rotlex FFV units to check these lenses.


Actually some of Rotlex's equipment isn't to far out their like many would think. They have equipment that would cost you in the same ball park as an automated lensometer. I don't think though that that is even necessary, checking localized powers like we do now with a standard lensometer can be accurate enough, but to know that the various compensations employed nowadays matches to the software and ultimately designers intended design is going to be paramount. I have heard before the trust us line and I of course will only do business with those that I trust, but at the same time their needs to be a way to verify results. Anyway I think what's on the market now FF wise is all pretty darn good and getter better by the day. More and more competition is breaking into the FF arena and eventually we will start seeing more of the pioneers start to share information about how their designs are comparatively better than others on the market and then we'll find out who's been cheating us with fancy new technology and who's been using fancy new technology to improve their product.

Until then I will continue to occasionally dip my toes into the FF waters.

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## AWTECH

> Are Rotflex gadgets accurate? If they can't be checked with a lens bench or something how would one know they were calibrated accurately?
> 
> chip


This type of equipment has no moving parts, other than the slide in and slide out for the lens to be measured.  Calibration is a done via software and can be done at anytime with no lens in  place.  If the software for this type of equipment is written correctly then it will either calibrate correctly or not.  If not you contact the manufacturer or know how to fix the problem.  (such as changing the expensive bulb).

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## xiaowei

> By the way (and Harry-Darryl, correct me if I'm wrong here):
> 
> Spherical aberration is an *on-axis* aberration
> 
> Conceptually, Coma is spherical aberration's *off-axis* first cousin.
> 
> Barry





> That's a good definition.


NO, NOT TRUE! SORRY!

What you are talking about applies to properly centered, rotationally symmetrical optical systems. These will/may have on-axis spherical aberration, but NO on-axis coma (already due to symmetry arguments), only off-axis coma (that´s what Seidel´s theory describes)

HOWEVER, a PAL is an extreme counterexample to a properly centered, rotationally symmetrical optical system. these systems also WILL have "on-axis" coma and trefoil due to the change of power along the progression channel within the pupil area, even Essilor CANNOT avoid it (as long as they don´t reduce the add to zero!), it´s only "Techno-Babel" (or maybe Techno-"Bubble"!?:) HAHA!)

In other, probably simpler terms, the "effective center of symmetry" of a PAL is way off the actual lens center due to the progressive zone, so you will ALWAYS use it "off-axis" -> Coma!

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## Barry Santini

Thanks, xiaowei, for your clarification. For ease of understanding coma, I was referring to, in a simple sense, a rotationally symmetric lens , which, of course, a progressive is not.

It's great to have you here to help clarify, explain and share your knowledge!

barry

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## xiaowei

> Thanks, xiaowei, for your clarification.  For ease of understanding coma, I was referring to, in a simple sense, a rotanially symmetric lens , which, of course, a progressive is not.
> 
> It's great to have you here to help clarify, explain and share your knowledge!
> 
> barry


Hi Barry, you´re welcome! 

"Unfortunatelly", this is (part of) everday`s work. The company I work for usually designs fully rotationally symmetrical optical systems that are also highly corrected for off-axis coma etc. (because we sometimes use 10 or more lenses), however, due to residual manufacturing tolerances and surface errors, the whole system will end up somewhat decentered and unsymmetrical and will also show on-axis coma on the order of some waves or even only some tenth of a wave, often too much for our (customer´s) purposes as semiconductor process inspection with nm resolution. The most cost-effective compromise (besides getting the single lens element as good and centered as feasible) is to have a fine adjustment step under interferometric or high magnification control for (usually) one or two selected element(s) to move the overall "center of symmetry" of the system back on axis and then it will behave almost "ideal" again!

Sincerely

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