# Optical Forums > Ophthalmic Optics >  Free form optimised single vision lenses

## 12345

Hi, would anyone here like to share their experiences in prescribing free form single vision lenses for their patients? Is the visual optics provided much better than the conventional lenses? Is the vision much better at night time for free form sv?

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## Barry Santini

Prtescribing? No.  Recommending, calculating and fabricating? Yes.

They're wonderful.

No ifs, ands or buts.

B

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## EyeCare Rich

> Prtescribing? No. Recommending, calculating and fabricating? Yes.
> 
> They're wonderful.
> 
> No ifs, ands or buts.
> 
> 
> 
> B


+1 Barry, right on the money!

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## Jacqui

*Some times* I agree with Barry Santini and this is one of them. I wear them and think they are much better.

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## IdentityOpticalLab

I usually argue that SV is a better example of the benefits of Freeform than PALs. PALs will always have a corridor and can never be made in violation of the minkwitz theorem. so the global design benefit that a well compensated freeform design can have is mostly in the distance area of a PAL, where as in a Freeform SV you can truly create edge to edge to edge clarity. this is especially true in higher prescritions, patients with astigmatism, and anytime you move a way from the ideal base curve.

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## jspayneii

> I usually argue that SV is a better example of the benefits of Freeform than PALs. PALs will always have a corridor and can never be made in violation of the minkwitz theorem. so the global design benefit that a well compensated freeform design can have is mostly in the distance area of a PAL, where as in a Freeform SV you can truly create edge to edge to edge clarity. this is especially true in higher prescritions, patients with astigmatism, and anytime you move a way from the ideal base curve.


+1

I have had good success with the freeform single vision.  Especially as the power increases.  I don't personally notice a difference, but I am only a -0.25 -0.75.  My brother in law is a -6.75 sph and loves the wider field of vision that it gives him.

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## Robert_S

We use the Nulux EP from Hoya mostly and four times out of five, if not more, the patient will describe their vision as the best they have ever had. 
They also love the fact that the Bi-Asphericity of the lenses greatly reduces the minification/magnification of their eyes.

It goes without saying that the Zeiss Individual SV achieves high patient satisfaction as well. 

I only wish more patients would elect to have 'Digital' single vision lenses.

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## eryn

I wear the Hoya Nulux EP 1.70 with Super Hi Vision A/R and love them! I'm give or take about a 
-5.00 in each eye.

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## Robert_S

I wish we could still get 1.70 here in the UK. Fantastic material, but Hoya have discontinued it. 

The only downside of it from my experience is that it tends to discolour quite quickly.

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## Jacqui

> I wish we could still get 1.70 here in the UK. Fantastic material, but Hoya have discontinued it. 
> 
> The only downside of it from my exerience is that it tends to discolour quite quickly.


It's still available from Tokai and Vision-ease

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## Robert_S

Thanks Jacqui!

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## Arsenal

> Prtescribing? No. Recommending, calculating and fabricating? Yes.
> 
> They're wonderful.
> 
> No ifs, ands or buts.
> 
> B


My patients love them. Makes me wish I wore glasses so I could "see" what its all about. They "see"m to live up to the hype.

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## Yeap

i have never prescribe any freeform SV. may i know usually what prescription you will prescribe that? as i seeing mostly are for high prescription? how about low prescription such as -1.00DS? 

thanks..

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## Barry Santini

1.00DS....no; unless it is to put this lens on a non-standard curve to be a soecific frame. Sometimes I will when trans is added, since i can source a FFSV with AR & trans for similar money than stk

B

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## Robert_S

I find that with anything over a +/-2.00 with anything over a 1.00 cyl, the patient will notice a difference. 

However, usually the patient will only notice a huge difference if the Sphere is over a +3.00 or -4.00, or if the cyl is above a 2.00, or if they are the engineer type.

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## Barry Santini

I think the FFSV upgrade difference is superior to a 0.25D sphere or cyl change, definitely

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## Robert_S

I would agree with that. It's probably worth some axis inaccuracy as well!

I'm getting very frustrated with our optometrist telling people they don't need new glasses, as if the only way to improve someone's vision is with an Rx change!

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## Yeap

Thanks for the good advice. i may consider it as upgrade for my patient. 

by the way, is Hoya Nulux EP also an FFSV? i thought is just a double aspherical stock lenses?

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## Robert_S

No. It appears in the catalogue as a stock product, but you will find the surfaced price is identical (unless you have different discounts for surfaced products), because it is a free-form surfaced lens, even if you order it as stock.

Here's what you should tell the patient they are getting if you are dispensing Nulux EP:

1) The sharpest vision possible through the centre of the lens. 
2) Excellent vision from edge to edge (the best peripheral vision).
3) The flattest, and usually thinnest prescription lens available (assuming you use the correct material).
4) Improved cosmetic appearance; less magnification/demagnification of objects through the lens, particularly the patient's eyes. 
5) A Hoya coating (a choice of Super HiVision or HiVision Longlife) -Hoya make the best coatings in the world. I usually tell the patients about their premium AR whilst I'm writing out the order. 

With all that, I don't know how some of them say no! Unfortunately some will, but the ones who invest in the lenses will be very impressed. Remember to only dispense it if the prescription is one that will benefit, as Barry and I discussed above.



PS. Sorry for sounding like I work for Hoya. I use the Zeiss Individual SV as well, and it's a great lens.

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## Yeap

HI Robert, great info you have it here.. honestly i prefer zeiss lenses for myself..

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## Robert_S

Well, the Zeiss Individual is a fantastic lens as well, though more expensive. I think that between that and the Nulux EP you couldn't go wrong. If you are comfortable with Zeiss, stick with Zeiss. 

Hoya certainly make better coatings though. My experience is that their lenses are thinner too, because of the double-sided surfacing.

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## Yeap

referring to double sided surfacing, NIkon also produce something similar. do you have any experience or feedback about that lens?

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## manoj_verma

seems NO OB Sells Rodenstock  :Unsure:

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## Robert_S

> referring to double sided surfacing, NIkon also produce something similar. do you have any experience or feedback about that lens?


I'm afraid I don't. I'm sorry.

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## sharpstick777

I would disagree.  Using Minkwitz a little, I think there is an enormous advantage in a backside add power in a myope, decreasing with increased hyperopia, to lower total distortion.  To use the old sand analogy for progressive lens distortion, it simply takes less sand to fill a bowl (like when we put the add on the back of a progressive) than when put the add on the front, because we are building a dome with sand.  It will take more sand to build that dome.

Also imagine a line that runs from the distance zone, through the "progressive" junk, then to the reading, across to the junk on the other side, and back to the distance.   In a free-form lens with a backside add we start with a steep concave for the distance, go moderate concave for the progressive area and have a flatter concave for the reading (all concave).  In a standard add on the front we start with a convex curve for the distance, through the progressive zone junk it turns to steep concave, and then back to steep convex for the reading, steep concave again, then back to convex (convex, steep concave, steep convex, steep concave, convex).  In a front side add lens you end up with focal points scattered over a wider area than a backside Free-form lens.   Although a backside add won't eliminate distortion, it lowers the potential total distortion because it keeps the progressive curve closer to the corrective curves of the RX, by definition thats less distortion.




> I usually argue that SV is a better example of the benefits of Freeform than PALs. PALs will always have a corridor and can never be made in violation of the minkwitz theorem. so the global design benefit that a well compensated freeform design can have is mostly in the distance area of a PAL, where as in a Freeform SV you can truly create edge to edge to edge clarity. this is especially true in higher prescritions, patients with astigmatism, and anytime you move a way from the ideal base curve.

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## sharpstick777

I think we forget what free-form lenses primarily do.  The first two primary things that free-form acheived was to compensate for the limited base curves of multifocals and bring a lens closer to true form optics, and to solve the issue of Oblique Marginal Astigmatism (which is really a base curve issue too).

As most of you know, every RX should have its own unique base curve, so a -2.00 should be on a different base curve than a -2.50, from a -2.75 etc.  We can't do this in multifocals simply because the total amount of blanks necessary would shoot up to about 25,000 for one progressive to cover every base curve in every add power.   Its not financially feasable.   As a result, we ususally end up with progressive blanks available on only 5 or 6 base curves instead of about 45, which is what we would need.

In single vision, we can solve this with true-or best form finished single vision lenses (or SV aspheric lenses that simulate true form optics) because we can use a SV finished lens for every axis (we just rotate the blank when laying it out).  We don't have add powers to stock, so it IS cost effective to make Finished SV using best form or aspheric optics.  A stock SV lens made with true form base curves can be stocked cost effectively.  In fact the Zeiss Punctal lenses in the 1930's did just this.

The problem with True form optics is that it runs a lot steeper than most people prefer cosmetically, so aspheric lens try to bridge that gap of providing better (simulated true-form optics) on a flatter base curve that is thinner and more appealing cosmetically.  We can improve optics immensely simply by using quality aspheric finished SV lens blanks.  

In the end either a SV finished True Form lens, or a quality finished aspheric SV (like Zeiss and Seiko) will give vision very close to Free-form, because the goal is same, simulated true form optics.  

The variable is the lab.  Many labs (for reasons beyond me) grind every lens, even SV, on simple base curves like 2,4,6, 8 etc.  Those lenses will NOT be close to true or best form optics.   They will not provide optimal vision.

The other issue is that Atoric lenses seem to be disappearing in finished SV (some manufacturers call theirs "double aspheric" now), so cyls over -1.25 will see some benifit in Free-form SV lenses over a stock lens that is not atoric.

So if you use a quality stock SV true form  lens, it will give you vision almost indistinguishable from Free-form in lower powers.  If you grind every lens, Free-form lenses will seem enormously better





> Hi, would anyone here like to share their experiences in prescribing free form single vision lenses for their patients? Is the visual optics provided much better than the conventional lenses? Is the vision much better at night time for free form sv?





> I find that with anything over a +/-2.00 with anything over a 1.00 cyl, the patient will notice a difference. 
> 
> However, usually the patient will only notice a huge difference if the Sphere is over a +3.00 or -4.00, or if the cyl is above a 2.00, or if they are the engineer type.

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## Barry Santini

Not sure of the "Punktal" facts. I know the original Punktal series was custom/individually computed for each RX rec'd, the precise radii calculated and individually made. They were expensive...about 10x normal stk meniscus lenses. 

When the corrected curve series were introduced, two things happped:

1. Depending on the manufacturer's chosen design tolerance, a select amount of power or cylinder or power/cyl error was accepted to reduce the need for individually caculated lenses, and....

(wait for it....)

2. The angular field of view that the design was intended to correct was reduced from Zeiss Punktal's original 60 degree, to the corected curve series 30 degree...a factor of 4x less optimized AREA.

FFSV, in a well dione design and production process, can equal or exceed Punktal's original 60 degree FOV correction.

For the newer, taller frames with high pupil placement above mechanical center, this can be quite significant, even in lower powered sphere's, especially under 2.00D, and especially if low abbe material is employed.

B

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## MakeOptics

Any shift of gaze larger than 20 degrees is usually accompanied by a head rotation.  A lens beyond 30 to 40 degrees field of view or apparent field of view is really just going to be unnecessary.  If we were to use technology to it's fullest the zones outside of this 40 degree optimal zone should be used to reduce cosmetics like thickness and/or weight.  To be fair the better lenses on the market take this into consideration and use outer zones of the lens to improve cosmetics.  Atoric lenses are obsolete, no longer necessary when the lens can be ground digitally providing the same effects, IMO.

I love the fact that I am not allowed to sell a coating as "No-Glare", but digital lenses are trying to be sold as reducing Chromatic Aberration.  True the effects of all aberrations are compounded so if the digital lens can reduce other optical aberrations the tolerance for Chromatic Aberration should in theory be higher but the lens or design still does not improve chr. abbe.

Sharpstick777, comparing Punktal lenses to today's digital lenses isn't fair.  The lenses in those days had to meet stricter tolerances, so although the technology and the equipment exists today to make a much more accurate product the research shows that a much less acceptable tolerance is accepted by the general population and optical "professionals", couple that with a lack of equipment designed to verify these new age lenses at the dispenser level and we have an opportunity ripe for abuse.  Currently a few labs exist that are abusing digitally surfaced lenses and I believe that in the next so many years a "white list" of trusted manufacturers and a "black list" of abusers will emerge.

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## Barry Santini

Phi trace:

I'm not sure I wholly agree with the default head rotation consensus.  Having participated in the design of 100 degree FOV telescope eyepieces, I can tell you that, without head rotation, and field imaged sharply this wide is...well, like nothin else you've ever seen!

B

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## Barry Santini

Sharpstick:

I think really well done SV FF lenses, in truth, often EXCEED the off-axis performance of true/best form fitting.

B

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## Barry Santini

> The problem with True form optics is that it runs a lot steeper than most people prefer cosmetically,


Interestingly, Darryl has pointed out that as the index goes up (higher), the appropriate true form curve needs to be STEEPER...something counterintuitive to me at first.

With this in mind, it's obvious why stk, non-aspheric poly SV has had such a bad rap for peripheral vision.

B

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## Wes

> Interestingly, Darryl has pointed out that as the index goes up (higher), the appropriate true form curve needs to be STEEPER...something counterintuitive to me at first.
> 
> With this in mind, it's obvious why stk, non-aspheric poly SV has had such a bad rap for peripheral vision.
> 
> B


That's very counterintuitive.  Do you have a link?

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## MakeOptics

> Phi trace:
> 
> I'm not sure I wholly agree with the default head rotation consensus.  Having participated in the design of 100 degree FOV telescope eyepieces, I can tell you that, without head rotation, and field imaged sharply this wide is...well, like nothin else you've ever seen!
> 
> B


Interesting fact, did you know that an Owl cannot rotate their eye's, that is the reason for 270 degree rotation of the head.  The reason I brought up that fun fact is that we shouldn't ignore head rotation, it's a factor in how we use our eyes.  

In the case of telescopes I have never designed one though I have though of a dobsonian design for it's simplicity if I were to ever design one.  Now field of view in a telescope describes the amount of sky you can see through the telescope, in a pair of ophthalmic lenses this is not the case, even though a particular field of view is designed for does not mean that beyond this field of view their is zero vision like in the telescope.  Also with the telescope you don't move the telescope around while looking through it, you align the telescope then you view through it, in essence the telescope has no head rotation.  I don't think they are really good comparisons, but your designing a telescope lens does put a bit more confidence in your ability to understand a lens so if it was confidence in your opinion that statement meant to evoke, then you have my confidence.  I would still disagree to the level of optimization necessary.  I think right now it may be a novelty and the higher the field of view, "the better" the better the lens must be and I'm all for it, yes I do sell SV FF lenses and love them, but I think we will begin to see lens optimization utilized differently in the next gen products.

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## Barry Santini

Phi Trace:

I look forward to havin a beer with you and discussing this subject.

B

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## Barry Santini

> That's very counterintuitive. Do you have a link?


No link.  Part of a discussion I engaged in with Darryl regarding this very point.

B

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## Wes

> Interestingly, Darryl has pointed out that as the index goes up (higher), the appropriate true form curve needs to be STEEPER...something counterintuitive to me at first.
> 
> With this in mind, it's obvious why stk, non-aspheric poly SV has had such a bad rap for peripheral vision.
> 
> B





> That's very counterintuitive.  Do you have a link?





> No link.  Part of a discussion I engaged in with Darryl regarding this very point.
> 
> B


Well, it goes against base curve surfacing charts, which have flatter curves with higher indices.  It also doesn't mesh well with Darryl's own spectacle optics analysis program.  Hmmm...

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## Barry Santini

Wes
Unless i got it backwards.....

???!!
B

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## MakeOptics

> Well, it goes against base curve surfacing charts, which have flatter curves with higher indices.  It also doesn't mesh well with Darryl's own spectacle optics analysis program.  Hmmm...


Wes,

In the spectacle optics program set the line to a power you want to read and then cycle through the different materials.  You'll notice for higher index materials the base curve goes up for the Ostwalt (or commonly used leg of the tschernings ellipse).  I recognized this a few years back when creating a tschernings analysis excel spread sheet.  It is a bit counter intuitive since in a surfacing lab we are taught to pull a base lower or flatter.  Either lens manufacturers give precedence towards cosmetics or they use aspherics for their lenses, but like you I was taught in the lab to pull a base or two lower.  It is later in life I learned to ignore those assumptions and go with science, but even then only if I knew the surface geometry of the lens.

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## Wes

> Wes,
> 
> In the spectacle optics program set the line to a power you want to read and then cycle through the different materials.  You'll notice for higher index materials the base curve goes up for the Ostwalt (or commonly used leg of the tschernings ellipse).  I recognized this a few years back when creating a tschernings analysis excel spread sheet.  It is a bit counter intuitive since in a surfacing lab we are taught to pull a base lower or flatter.  Either lens manufacturers give precedence towards cosmetics or they use aspherics for their lenses, but like you I was taught in the lab to pull a base or two lower.  It is later in life I learned to ignore those assumptions and go with science, but even then only if I knew the surface geometry of the lens.


I find I am guilty of some ignorance (and a bit of mis-speaking) of which I was unaware.  To the mis-speaking, I shouldn't have said flatter, what I was thinking was "closer to 6 diopters" which seems to apply well to minus rx's.  I assumed that applied to plus rx's being "closer to 6 diopters" as the index goes up.  Following that line of thinking, I experimented.  If you re-set the surface curvature index to standard tooling, which is what we think of as the curve as opposed to actual surface power, you will find that in higher plus rx's (above +3 or so), it is "closer to 6 diopters", if only marginally.  

Barry & Phi, thanks for the education!

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## MakeOptics

> I find I am guilty of some ignorance (and a bit of mis-speaking) of which I was unaware.  To the mis-speaking, I shouldn't have said flatter, what I was thinking was "closer to 6 diopters" which seems to apply well to minus rx's.  I assumed that applied to plus rx's being "closer to 6 diopters" as the index goes up.  Following that line of thinking, I experimented.  If you re-set the surface curvature index to standard tooling, which is what we think of as the curve as opposed to actual surface power, you will find that in higher plus rx's (above +3 or so), it is "closer to 6 diopters", if only marginally.  
> 
> Barry & Phi, thanks for the education!


I don't know if I'd call that education I seem to recall having a similar conversaton on a similar topic with you some time ago, as the saying goes you'll probably forget more about optics then most people know.  The trick is to surround yourself with people that remember the parts that you don't remember and you create an optical monster.

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## Darryl Meister

> Well, it goes against base curve surfacing charts, which have flatter curves with higher indices. It also doesn't mesh well with Darryl's own spectacle optics analysis program


As you guys have noted using *Spectacle Optics*, high-index lenses with spherical front curves would need steeper front curves in order to eliminate off-axis marginal astigmatism.

Nevertheless, flatter base curves are often used for non-aspheric high-index lens materials primarily for cosmetic reasons, not optical reasons. Most high-index lenses are made with aspheric front curves, however, so the front curve can be made as flat as desired.

It is interesting to note that high-index lens materials also suffer from slightly higher levels of off-axis power or astigmatic error, due to a greater departure of Petzval's surface from the ideal imaging points of the eye (i.e., the far-point sphere) as the refractive index increases.

Consequently, between the slightly greater power errors and the increased lateral chromatic aberration that also contributes to off-axis blur, it becomes even more crucial to use aspheric, atoric, or optimized free-form designs with high-index lens materials.

Best regards,
Darryl

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## sharpstick777

I agree that it can Barry, but it depends on the amount of astigmatism IMHO.  The difference I am trying to point out is not the FF is the same, but in SV FF we are not going to get the Wow factor as fast or as much as a FF Progressive, simply because we can (possibly) make a SV Lens closer to best form optics without much work.  




> Sharpstick:
> 
> I think really well done SV FF lenses, in truth, often EXCEED the off-axis performance of true/best form fitting.
> 
> B

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## Barry Santini

> I agree that it can Barry, but it depends on the amount of astigmatism IMHO. The difference I am trying to point out is not the FF is the same, but in SV FF we are not going to get the Wow factor as fast or as much as a FF Progressive, simply because we can (possibly) make a SV Lens closer to best form optics without much work.


Most of my comparative statements about the vision improvement with FFSV lenses are framed against both stk and surfaced lenses that rarely, if ever, employ the optimal BC in compliancce with best form fitting. And certainly do not take into account any frame wrap angles greater than 7 degrees, which is common.

Barry

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## MakeOptics

> Most of my comparative statements about the vision improvement with FFSV lenses are framed asint both stk and surfaced lenses that raraely, if ever, employ the optimal BC in compliancce with best form fitting. And certainly do not take into acoount any frame wrap angles greater than 7 degrees, which is common.
> 
> Barry


Interesting, I know what you're getting at.  It's also the reason why some people will drive a bentley while others drive a hyundai.  The hyundai driver might not see the logic in driving the bentley.  Ultimately your right in the fact that an optimized lens will offer greater precision if utilized properly, I don't know if everyone will notice the improvement but to some even a slight improvement is worth every penny.  Who am I to argue against the premium sale.

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## Barry Santini

> Interesting, I know what you're getting at.  It's also the reason why some people will drive a bentley while others drive a hyundai.  The hyundai driver might not see the logic in driving the bentley.  Ultimately your right in the fact that an optimized lens will offer greater precision if utilized properly, I don't know if everyone will notice the improvement but to some even a slight improvement is worth every penny.  Who am I to argue against the premium sale.


I have no customers, aka zilch, that do not see the difference with FFSV. At leadt for te Rxs I suggest them for.

I've already had clients opt for conventional stk poly lenses to save the $120 upcharge for FFSV (CR-39).

There are no more unhappy faces when they discover the "whoa" of going without FFSV. Of course I was happy (to eat) the stk poly and charge the difference for the upgrade to FF. It's a small price to pay for their future commitment to premium FF.

B

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## glucocq78

I have dispensed quite a few free form single vision lenses to px's and I also wear them. So far the response from my px's has been positive with most people remarking that their new lenses seem clearer and not as distorted. So far I have only dispensed medium to high RX's as i think on a simple rx up to about +-4.00  it is a little bit harder to justify the increased price. As for myself I am quite myopic and I have a -4.50 cyl in my rt eye and a -2.50 cyl in the left I definateley feel that they are better than conventional lenses. If I have any px's with rx's similar to mine I always recommend free form lenses.
http://cheapspecsdiscountglassesscardiff.co.uk

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## CoolOptician

Yes, our patients who elected to upgrade loved the Hoya product we used.  All the cases I can remember always commented on the difference in clarity.  I also have had superb experience with Hoya coatings, as well as their lenses.  Just overall, super experience.

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## Robert_S

> I have dispensed quite a few free form single vision lenses to px's and I also wear them. So far the response from my px's has been positive with most people remarking that their new lenses seem clearer and not as distorted. So far I have only dispensed medium to high RX's as i think on a simple rx up to about +-4.00  it is a little bit harder to justify the increased price. As for myself I am quite myopic and I have a -4.50 cyl in my rt eye and a -2.50 cyl in the left I definateley feel that they are better than conventional lenses. If I have any px's with rx's similar to mine I always recommend free form lenses.
> http://cheapspecsdiscountglassesscardiff.co.uk



I love the irony of you recommending better products for people whilst selling glasses online. If quality is so important to you, how can you justify that practice? Well, I guess money is more important.

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## toddchaney

Free-form single vision lenses are more preferred as they provide high precision of free form surfacing which can produce lens surfaces over 100 times more accurate. Sophisticated lens design software employed in free form single vision lenses allow correction levels beyond corrective curve lenses. Free-form lenses also reduce glare and halo effects caused by light sources at night, such as car headlights.

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## Robert Martellaro

> Free-form single vision lenses are more preferred as they provide high precision of free form surfacing which can produce lens surfaces over 100 times more accurate.


Any improvement in dioptric power accuracy over traditionally surfaced or finished lenses is not clinically significant. 




> Sophisticated lens design software employed in free form single vision lenses allow correction levels beyond corrective curve lenses.


Reduction in aberrations and power error is certainly welcome, when it exists, but does require  extremely capable software and an optician who can determine and place the optics in an optimum position, and also be able to communicate that position to the software/fabricator.




> Free-form lenses also reduce glare and halo effects caused by light sources at night, such as car headlights.


Not generally due to lens design. Coated optics (anti-reflection) will reduce ghost images and increase light transmission.

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## DanLiv

> Free-form single vision lenses are more preferred as they provide high precision of free form surfacing which can produce lens surfaces over 100 times more accurate. Sophisticated lens design software employed in free form single vision lenses allow correction levels beyond corrective curve lenses. Free-form lenses also reduce glare and halo effects caused by light sources at night, such as car headlights.


some of this is true, some false, but all of it is pretty irrelevant to the benefits of free form optics. Sharpstick's original post and Robert's analysis are correct.

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## Bey Patrick

Can ANYONE!!! Send me some surfacing charts...

I am training a new employee and I really need to provide them with some steady info.
I REALLY NEED YOUR HELP  :Redface:

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## farawayC

Interesting thread from the dead.

To what degree can best fit base curves be "ignored" in SVFF design? Could you create an "inverse" lens with convex side toward the eye and concave side facing forwards with minimal distortion?

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