# Optical Forums > Progressive Lens Discussion Forum >  Thickness Problem with Physio 360 1.74

## sharpstick777

Problem: New lenses are coming in from the lab very thick, thicker than his old 1.67's (his RX actually decreased).

RX:
+8.75  -3.25  x018   pd 32
+9.25  -3.25  x155   pd 31
add +1.75 OU

Frame: Flexon 422 Oval Shape 48/19  29.5mm B  48mm ED

Lens: Physio 360 1.74

I have received 2 pairs of 1.74 Physio 360's 1.74 with a min. edge thickness of 3.75 mm, CT of 9.5.  His old 1.67's are at 1.5mm edge with a slightly higher RX and are way thinnner (CT of aprox 7mm).  Patient is obviously unsatisfied that his 1.74's are way thicker than his old 1.67's.
The lab is telling me that this is the thinnest they can do these lenses, but can't tell me why. 

Obviously switching lenses is an option, switching frames is not and his small oval is almost perfect for this RX.  Anyone else have trouble with small frames in the Physio 360?  And if we switched him to another Atoric lens, what would it be?  1.74 seemed like a best choice in material.  Any answers would be appreciated.

Sharpstick

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## Craig

> Problem: New lenses are coming in from the lab very thick, thicker than his old 1.67's (his RX actually decreased).
> 
> RX:
> +8.75  -3.25  x018   pd 32
> +9.25  -3.25  x155   pd 31
> add +1.75 OU
> 
> Frame: Flexon 422 Oval Shape 48/19  29.5mm B  48mm ED
> 
> ...


You are in trouble with getting thin plus lenses from the 1.74 360 products at this point!  They do have an 8 base lens that would be nice, but at that edge thickness they are way off on the calculations and are using bad data. The next best option is to call a lab who understands that the thinnest edge should be 1.5mm.
I would send it to Pech and have them calculate the thickness with various base curves that available in high index.  Actually Harry should have the best choice for this type of RX in his head.  I am not sure if a 9 base on 1.6 is better served than an 8 or 10 base.

Harry, where are you?

Craig

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## sharpstick777

> I would send it to Pech and have them calculate the thickness with various base curves that available in high index. Actually Harry should have the best choice for this type of RX in his head. I am not sure if a 9 base on 1.6 is better served than an 8 or 10 base.
> 
> Harry, where are you?
> 
> Craig


I have not had good luck with Pech myself.

Sharpstick

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## For-Life

Why can't the lab do a knife edge?   That is where your thickness is that.

Also, check the base curves.

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## Jacqui

> Why can't the lab do a knife edge?   That is where your thickness is that.
> 
> Also, check the base curves.


It's probably a software problem. It's a no-brainer when using the older equipment to get a knife edge everytime. This is one of the problems with the new ultra-modern, computer driven labs. The computers don't know how to compensate or watch the lens and the operaters (I can't call them opticians or lab techs) don't have a clue.

I would suggest trying a different lab, one that knows how to make lenses, not just punch numbers into a computer program.

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## scriptfiller

His old ones were probably surfaced with the frame enclosed.  Are you ordering uncut, then edging them yourself?  

I've noticed that with high plus, having the frame enclosed to the lab is the only way to get a decent thickness.

I don't find 1.74 index noticeabley thinner that 1.67.  I had a pat come in needing a quick lense replacement, her old ones were 1.74, I ordered stock 1.67 and compared them the 1.67 was maybe .5mm thinner.

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## C-10

return the lenses and tell them you want a 6.5  center the edge thickness will come out to 1.0

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## HarryChiling

If you look at the VCA communications standards you will start to realize that the problem is int he software. A simple fomula exists for spheres, cylinders, aspheres, even atorics. But these new FF lenses use deformed conicoids and in the standards every point doesn't have to be specified you can use wildcards "?" for some of the points and the computer will calculate the point beased on the available data. The standard also dictates that the center points Z measure or coordinate is always zero so that will always be your start point, so to specify the edge would mean you would have to work from the edge in to the center and maybe even run through a few iterations to make sure you have an acceptabel thickness. Some FF lenses are still using rudimetary software to calculate the back surface. The technolgy no matter what you hear is still in it's infancy, it still has hicups. If it was google it woudl still be in BETA.

Craig, I'd have to go with high abbe lower index especially on this one.  the lens being thick will have an effect on the transmission and the power will definately require a better abbe.  Also a harder design is really really necessary you want something that is as wide in the channels as possible a backside design would be best.  This is due to the ring scotoma effect of high plus lenses, this will destroy the channel of a front surface progressive.  Maybe the unique in 1.67 aspheric front surface if possible or a hoya id in 1.70.

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## optigrrl

> If you look at the VCA communications standards you will start to realize that the problem is int he software. A simple fomula exists for spheres, cylinders, aspheres, even atorics. But these new FF lenses use deformed conicoids and in the standards every point doesn't have to be specified you can use wildcards "?" for some of the points and the computer will calculate the point beased on the available data. The standard also dictates that the center points Z measure or coordinate is always zero so that will always be your start point, so to specify the edge would mean you would have to work from the edge in to the center and maybe even run through a few iterations to make sure you have an acceptabel thickness. Some FF lenses are still using rudimetary software to calculate the back surface. The technolgy no matter what you hear is still in it's infancy, it still has hicups. If it was google it woudl still be in BETA.
> 
> Craig, I'd have to go with high abbe lower index especially on this one. the lens being thick will have an effect on the transmission and the power will definately require a better abbe. Also a harder design is really really necessary you want something that is as wide in the channels as possible a backside design would be best. This is due to the ring scotoma effect of high plus lenses, this will destroy the channel of a front surface progressive. Maybe the unique in 1.67 aspheric front surface if possible or a hoya id in 1.70.


In addition to having better optics, the Hoya 1.70 is about 8% thinner than the 1.74 at that power.

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## KStraker

> It's probably a software problem. It's a no-brainer when using the older equipment to get a knife edge everytime. This is one of the problems with the new ultra-modern, computer driven labs. The computers don't know how to compensate or watch the lens and the operaters (I can't call them opticians or lab techs) don't have a clue.
> 
> I would suggest trying a different lab, one that knows how to make lenses, not just punch numbers into a computer program.


So with this new fangled stuff you can't change the edge thickness? Makes me happy we still have a copy of RXP3. It's pretty simple, when you see the field for edge thickness, you input 1.5 instead of the 2.2 that our system defaults to. Tell the lab you don't care what kind of lens it is. The thinnest edge should be no thicker than the width of the eyewire.

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## Jacqui

> Tell the lab you don't care what kind of lens it is. The thinnest edge should be no thicker than the width of the eyewire.



That will cause confusion :D :D :D

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## HarryChiling

Was the ET specified?

If it was then it doesn't meet the ANSI standard, if it doesn't then they're just cosmetically unappealing.

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## RT

> If you look at the VCA communications standards you will start to realize that the problem is int he software.


I'm don't think that those are the dots that I would have connected here.  I'm sure that Shanbaum, as the Chairman of The Vision Council's Device Communications Standard (DCS) Committee would extend an invitation to you to join us at one of the meetings so you could point out how the standard created this particular pair of thick lenses.  Next DCS meeting is in Nashville next week.

More likely, what is happening is that the lab is running into limitations with their blocking system.  Since FreeForm processes do not typically use wax blocking, the generator is unable to cut into the blocking material (or else it would ruin the lathe).  On a high plus lens going into a smallish frame, therefore, the lens has to come out thicker to keep the lathe from hitting the block.  When the lens is then edged out of the resulting surfaced lens, the edge thickness is thicker than desired.  It all depends upon the diameter of the blocks available to the FreeForm process. I have no idea if smaller diameter blocks can be used in that particular lab's process.

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## RT

> Was the ET specified?
> 
> If it was then it doesn't meet the ANSI standard, if it doesn't then they're just cosmetically unappealing.


Actually, a careful reading of ANSI Z80.1-2005 shows no mention of sepcifying edge thickness. If a CENTER thickness is specified, the resultant thickness must be within +- 0.3mm (however, FDA regulations always require that the lens be able to pass dropball testing).

One of the reasons that ANSI Z80.1 is not a "standard" but a "recommendation" is that ECP requests can over-constrain a job. If, for example, specifying edge thickness really were part of Z80.1, what would prevent someone for asking for a (-8.00) power with a 1.5 mm edge thickness? Of course the lens cannot possibly be made to that edge thickness.

One thing is for certain. The lab certainly has bungled this job, and even worse, bungled the communications to the ECP regarding the job. If there is some technical reason that the lab can't fabricate THAT lens thinner, they should indicate if they could fabricate a DIFFERENT lens thinner. The shoulder shrug is pretty unsatisfactory.

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## HarryChiling

> I'm don't think that those are the dots that I would have connected here. I'm sure that Shanbaum, as the Chairman of The Vision Council's Device Communications Standard (DCS) Committee would extend an invitation to you to join us at one of the meetings so you could point out how the standard created this particular pair of thick lenses. Next DCS meeting is in Nashville next week.
> 
> More likely, what is happening is that the lab is running into limitations with their blocking system. Since FreeForm processes do not typically use wax blocking, the generator is unable to cut into the blocking material (or else it would ruin the lathe). On a high plus lens going into a smallish frame, therefore, the lens has to come out thicker to keep the lathe from hitting the block. When the lens is then edged out of the resulting surfaced lens, the edge thickness is thicker than desired. It all depends upon the diameter of the blocks available to the FreeForm process. I have no idea if smaller diameter blocks can be used in that particular lab's process.


shanbaum went over the mistake I made, teh standard still allows as much or as little data as possible to be feed into the process.  I did not even consider blocks but that's an interesting note.

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## JanMueller

It's clear that a freeform product like the Physio is thicker than the former lenses that were probably a conventional design...
Always remember that a FF MUST be thicker than other designs.
It sounds dumb, but I have had great success with Impression Hyperop 1.67 from Rodenstock (I am german...) although it is a FF. In Germany we get the lenses uncut. With Rodenstock knowing the exact data of the frame we get the thinnest lenses I can think of.

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## JanMueller

It's clear that a freeform product like the Physio is thicker than the former lenses that were probably a conventional design...
Always remember that a FF MUST be thicker than other designs.
It sounds dumb, but I have had great success with Impression Hyperop 1.67 from Rodenstock (I am german...) although it is a FF. In Germany we get the lenses uncut. With Rodenstock knowing the exact data of the frame we get the thinnest lenses I can think of.

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## Fezz

> Always remember that a FF MUST be thicker than other designs.



Really?

Why?

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## JanMueller

I have read so many articles from you, so it's an honour to talk to you...
(Excuse my school English, please).
If there are high plus powers combined with high additions, then the guys making the lens have to use higher base curve to get the same reading power like a conventional front surface design.
So it has to get thicker...

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## Fezz

> I have read so many articles from you, so it's an honour to talk to you...
> (Excuse my school English, please).
> If there are high plus powers combined with high additions, then the guys making the lens have to use higher base curve to get the same reading power like a conventional front surface design.
> So it has to get thicker...



The honor is all mine!

Welcome to Optiboard!!!!

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## JanMueller

Thank you Fezz. Like it here a lot.

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## sharpstick777

But our local rep and Hoya lab kind-a suck.  




> In addition to having better optics, the Hoya 1.70 is about 8% thinner than the 1.74 at that power.

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## sharpstick777

> It's probably a software problem...
> 
> I would suggest trying a different lab, one that knows how to make lenses, not just punch numbers into a computer program.


All Essilor 1.74's 'Progressives right now come directly out of Dallas so it really doesn't matter what lab I choose, the problems is with Essilor.

It is a software issue I am told... they have dropped the thickness a little but not all the distance we need.  I think it has to do with the system default min's set too high.  They imput the correct data but the software overrides it.  No success yet, and although I hate Hoya I may send the job to them.

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## sharpstick777

> In Germany we get the lenses uncut. With Rodenstock knowing the exact data of the frame we get the thinnest lenses I can think of.


Rodenstock left the US market for 2 years.  Although they are launching products again here I am not in any hurry to start selling the lenses (although I was a HUGE Multigressive fan).  Not many labs are stocking Rodenstock blanks because they kind of burnt their bridges a bit...

Sharpstick

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## JanMueller

I am not that familiar with Essilor but if you choose a semi finished PAL like Comfort in 1.67 (is it available in 1.74???) where they *don't* have to calculate, shouldn't it be thinner ? Maybe there is a chance not to change to Hoya.

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## xiaowei

> If there are high plus powers combined with high additions, then the guys making the lens *have to use higher base curve to get the same reading power like a conventional front surface design*.
> So it has to get thicker...


Sorry to interrupt, but IMHO this is the original claim only put in different words. WHY would this be necessary compared to a non FF design? Why doesn´t it apply for a conventional design, too?

And also, in a "true, full" FF design, there would no longer be any "base curves" in the traditional sense, i.e. no fixed limited choice.

Also "conventional wisdom" (i.e. advertising;)) usually claims that aspheric designs (where you could use more degrees of freedom just in a FF design),
will lead to "thinner" lenses (in the sense of less bending) for the same amount of off-axis gazing. I know this might collide with PAL "design rules", but a good compromise here is just what makes a successful PAL.

Sincerely

XW

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## JanMueller

Just order two lenses which have the same diameter, power and material and you will see it's thicker.
I have done it and it was obvious.
I got the information from an article of an german lens manufacturer who wrote this in the most important german journal of opticians.
He was the first one who told us the truth although he has his own FreeForm in stock.
If somebody spits into a mould, makes it warm and tells you that what comes out is a FreeForm then this must not be better then a conventional design.

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## Bob MacNeil

Good frame selection,   aspherics are more important then index selection for high plus Rx work,  lab may be having problems with lens diameter knifing out on surfacing chuck  ask for 0.5m/m edge at frame 180 temple side.

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## KStraker

> But our local rep and Hoya lab kind-a suck.


I just received a 1.67 Id lifestyle from Hoya. Rx is: 
+6.75-1.25X150
+7.00-1.50X10
+2.25 ADD
The thinnest edge is just inside the rim of the frame(full metal). I refuse to believe that a $500,000 generator is limited by a $5.00 block(as some have suggested). Standard or freeform, spherical or aspheric, it's a chunk of plastic and you should be able to control the parameters of the finished lens. If your lab can't do a good enough job, order a lifestyle id from Hoya Atlanta.

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## LENNY

> More likely, what is happening is that the lab is running into limitations with their blocking system. Since FreeForm processes do not typically use wax blocking, the generator is unable to cut into the blocking material (or else it would ruin the lathe). On a high plus lens going into a smallish frame, therefore, the lens has to come out thicker to keep the lathe from hitting the block. When the lens is then edged out of the resulting surfaced lens, the edge thickness is thicker than desired. It all depends upon the diameter of the blocks available to the FreeForm process. I have no idea if smaller diameter blocks can be used in that particular lab's process.


So there was no 1.0 edges on the smaller lenses when alloy is used?

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## jjbons

> But our local rep and Hoya lab kind-a suck.


If you don't like your local HOYA lab, HOYA has over 110 independant distribution options. They can't all suck.

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## gemstone

Thickness is pretty basic for quality.  If they can't get the thickness correct, how do you think the rest of the quality is going to be?  Go with a Sola or Hoya product.

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## Floyd

Edge thickness should be 1.0(or less) on high plus lenses. I've had no issue getting 1.74 360's at correct edge thickness. I think Plus lenses are a little tricky to guess what you should use but at that high of a power 1.74 would be my choice. 
As far as Uncuts go on previous post, I agree. Even with A,B and ED measurements, a traced frame seems to always work better.

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## RT

> I just received a 1.67 Id lifestyle from Hoya. Rx is: 
> +6.75-1.25X150
> +7.00-1.50X10
> +2.25 ADD


Although Hoya appreciates the positive mention, the key thing about the original post is that the plus lens is going into A VERY SMALL FRAME.  The power alone is not what is causing the problem...it is the combination of the high plus and the small frame.  Any lab using a blocking method that does not allow the generator tool to cut into the blocking material will have a problem with that combination--and it doesn't matter if it is a FreeForm progressive or a conventional progressive.  It would be unfair to suggest that one or two lens manufacturers somehow have a monopoly on correctly calculating thickness on plus lenses.

Fortunately, several companies showed new blocking systems at last week's OLA convention that could relieve the problem.




> I refuse to believe that a $500,000 generator is limited by a $5.00 block


I could give you a long list of things that I refuse to believe about opticianry, but yikes--I'm afraid those are true too.  And it's not the $5.00 block, it's the incredibly expensive diamond cutting tool that is being protected.




> So there was no 1.0 edges on the smaller lenses when alloy is used?


It depends upon the size of the frame, how high the Rx is, and the actual process used (blocking method etc.).  Unfortunately, there's no hard and fast rule.

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## KStraker

> Although Hoya appreciates the positive mention, the key thing about the original post is that the plus lens is going into A VERY SMALL FRAME. The power alone is not what is causing the problem...it is the combination of the high plus and the small frame. Any lab using a blocking method that does not allow the generator tool to cut into the blocking material will have a problem with that combination--and it doesn't matter if it is a FreeForm progressive or a conventional progressive. It would be unfair to suggest that one or two lens manufacturers somehow have a monopoly on correctly calculating thickness on plus lenses.
> 
> Fortunately, several companies showed new blocking systems at last week's OLA convention that could relieve the problem.
> 
> 
> 
> I could give you a long list of things that I refuse to believe about opticianry, but yikes--I'm afraid those are true too. And it's not the $5.00 block, it's the incredibly expensive diamond cutting tool that is being protected.
> 
> 
> It depends upon the size of the frame, how high the Rx is, and the actual process used (blocking method etc.). Unfortunately, there's no hard and fast rule.


We have a surfacing lab, so I'm familiar with those issues. My rx calculator somes up with a minimum blank size of 60mm. My smallest block is 55mm wide. How big are the blocks for a free form generator? Why don't they make a small one to accomodate this kind of work?  

Oops, on a reread, looks like someone is addressing this issue.

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## sharpstick777

Out of RX range for an ID Lifestyle... 

Hoya ID would work but its not a VSP lens.   





> If you don't like your local HOYA lab, HOYA has over 110 independant distribution options. They can't all suck.


 
You're right but I don't want to open another account with another lab.

Sharpstick

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## KStraker

> Out of RX range for an ID Lifestyle... 
> 
> Hoya ID would work but its not a VSP lens.   
> 
> 
> 
> 
> 
> You're right but I don't want to open another account with another lab.
> ...


The free form stuff will be forwarded to a particular facility. It will not be done by your local Hoya lab.

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## ezrich

sharpstick777 essilor dallas is bad news. we quit doing ipseo's, switched to autograph's. try digital eye lab 1 866 866 8673 in ny.

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## sharpstick777

> sharpstick777 essilor dallas is bad news. we quit doing ipseo's, switched to autograph's. try digital eye lab 1 866 866 8673 in ny.


I have noticed and increase in remakes, and decrease in turn around time, and overall drop in the lenses we get from Dallas (just barely within tolerance instead of dead on).

Anyone from Essilor care to comment on these issues? Pete have you seen this thread?

Update: The job is in Dallas as we speak, they say they are sending lenses with satisfactory thickness ( I believe we are on remake number 8)? They tell me the problem is a software issue, not an equipment issue. My lab has given me Physio 1.67's as loaner lenses since we are now 6 or 7 weeks into this. I do want him into an Atoric design with his RX though.

Sharpstick...
and getting sharper...

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## gemstone

Really?  Do you think that the #1 priority for the big E is getting proper thickness on one lens on one order?!!  Really?!! Who do you think you are?

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## sharpstick777

> Really? Do you think that the #1 priority for the big E is getting proper thickness on one lens on one order?!! Really?!! Who do you think you are?


Um, how did I get flamed in this?  I never said I was anything or anyone special.  Essilor tells me they are still trying to work on the issue, all I did was update the thread.  

I think I am an Optician who asked for a lens in a certain perscription that was within the manufacturers stated parameters.  Where do you read into this that I am anything more?

Sharpstick...

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## gemstone

> Um, how did I get flamed in this? I never said I was anything or anyone special. Essilor tells me they are still trying to work on the issue, all I did was update the thread. 
> 
> I think I am an Optician who asked for a lens in a certain perscription that was within the manufacturers stated parameters. Where do you read into this that I am anything more?
> 
> Sharpstick...


 Sorry.  You could not see my toung in my cheek when I was typing that.  Please don't take me too seriously.

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## sharpstick777

> Sorry. You could not see my toung in my cheek when I was typing that. Please don't take me too seriously.


Its all good Gemstone...

Physio 360's arrived today in great shape.  Rx was dead on, min edge thickness was 1.0mm and 1.6mm.  The lab did them gratis for the delay.

Although I really appreciate Essilor going to work for this one patient and willing to chew through a ton of lenses to get it right, I wonder why they didnt catch this potential issue when they were doing testing?  Its my understanding that before a paramater becomes official they test it first.  

When Definity launched I think you could only order it up to a -2.00 because testing had not been done on higher powers.

Unlike some I actually have been impressed with Essilor on a few occaisions, and I appreciate the work they did to get this job right.  But I would love to hear from an Essilor suit to why testing didn't catch this.

Sharpstick

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## HarryChiling

Can anyone here imagine what a knife edge on a lens would do to a conformable lap?  Chances are even if they got it to the 1.0 or less edge thickness the lap would be destroyed and you might get a lens that had issues polishing out.  Just another potential issue I could see causing some of the issues.

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