verifying progressives ...oh my!

[pseudonym]

You are not getting the right power according to who? How are they reading the "correct" power? Lensometer or the engraved markings?

Engraved markings.

[mullo]

What was the power of each lens in the 180° meridian of the spectacles in question?

The second option is frightening considering that I saw a pair of glasses in the remake bin today that came in with a 91 pd. I asked if they would let me look at them in the lensometer, and sure enough I couldn't begin to get them centered.

New question: 91 pd is obviously wrong and it was even marked 91 pd on the lab ticket! Don't labs have some kind of parameter for pd's that would reject them outright before they ever reach the shop? Or at least have the parameter set at (say) 74 which is the largest pd I've personally seen that would flag them for a technician to check and possibly manually override in the case of giantesses and ogres?

[Chris Ryser]

Iam really enjoying this thread how the guys and gals are finding distorted parts on lenses that should not be so.

Maybe the lens companies should go back to the drawing board or drop the prices for these lenses until they can come up with something that will pass the lensometer test of a finished lens.

Has anybody found a clean undistorted reading pat yet ?

[pseudonym]

What was the power of each lens in the 180° meridian of the spectacles in question?

Power? On the 180th? I thought pd was a purely linear measure.

The Rx was OD +0.50 -0.75 X 94 (calculator calculator...-0.25 on the 180th)
OS was +0.25-0.50X80 so (tap tap tap...-0.23 on the 180th)

Much as it pains me to admit it, the pd mistake was mine. The lab *did* list the pd as 91 on the ticket, but I had been diddling with the prism ring earlier and failed to zero it out. So the glasses were reading W-I-D-E when they were fine.

I still would like to know how the lab can list the pd as 91 when it was really 58.

[pseudonym]

Iam really enjoying this thread how the guys and gals are finding distorted parts on lenses that should not be so.

Things looked better today after I used Laurie's trick of reading far down into the lens. I had to lift the shallower specs up off the lens table but I got readings that were close to the etched numbers. These readings still didn't seem to be related to the infamous "verification circle" though. I suspect I'm just looking for the power that is supposed to be somewhere in the lower half of the lens.

[HarryChiling]

....or...we could only dispense PALs that promise 100 percent of the Add. And, verify it with our lensometer to see that it is true. If not, send it back.

Great advice.

The second option is frightening considering that I saw a pair of glasses in the remake bin today that came in with a 91 pd. I asked if they would let me look at them in the lensometer, and sure enough I couldn't begin to get them centered.

New question: 91 pd is obviously wrong and it was even marked 91 pd on the lab ticket! Don't labs have some kind of parameter for pd's that would reject them outright before they ever reach the shop? Or at least have the parameter set at (say) 74 which is the largest pd I've personally seen that would flag them for a technician to check and possibly manually override in the case of giantesses and ogres?

Most software will flag this kind of thing the DVI I use to order from the lab will flag based on negative decentration, so will Innovations. I don't think Visual Lab Pro does and that's the three I have worked with overthe years. The larger labs do flag this kind of thing and most will call to verify a 91 PD should never get through, but also keep in mind that in order for you to get a 91 PD, someone had to order it, so the problem starts in your office. Now on the labs end they try their best to prevent all unnecessary remakes because it costs them time and money, but at some point the accounts need to take responsibility for themselves as well.

Using the proper cutout chart isn't always possible with donated specs- some of these things are strictly disco bondage headgear. I've been told to use any 4mm template if I can't id the logo.

If you had to use any template I would go with the 6mm above template as this is the highest fitting above PRP I have seen any progressive to have, although as long as you can identify that the lens is not a zeiss lens a 4mm template could do the trick as well. I guess in the absence of the proper tools (PAL Identifier, and cut out charts) you could always check at the lowest point on the frame as the near reference point, for the distance reference point I would recomend checking based on an average template and not a just the top most portion of the lens as some desings will start to change power if their is a significant room above the distance reference point. For example look at the maps below of a compact ultra. The darkest blue indicates plano sphere power and each ring of color aroudn it indicates a +0.12 increase in power.

[bob_f_aboc]

Power? On the 180th? I thought pd was a purely linear measure.

The Rx was OD +0.50 -0.75 X 94 (calculator calculator...-0.25 on the 180th)
OS was +0.25-0.50X80 so (tap tap tap...-0.23 on the 180th)

Much as it pains me to admit it, the pd mistake was mine. The lab *did* list the pd as 91 on the ticket, but I had been diddling with the prism ring earlier and failed to zero it out. So the glasses were reading W-I-D-E when they were fine.

I still would like to know how the lab can list the pd as 91 when it was really 58.

So total prism in this pair was still less than 1 diopter even at a PD of 91. (.792D) There are times I wish my lab was that good!

[lensgrinder]

I'm getting ok with bifocals, but these progressives are a whole nother thing. I'm getting the Rx ok, but I can't figure out how to verify the add. Yesterday I found out that they just look for the number etched on the lens and write that down as the add. Fair enough, but I can't do that on the boards.

Where did you get this information from?
NC State Boards allow you to read the etched power.

[Eva]

I realize that opticians in the field merely note the etched number and write it down as the ADD, but what is the reason for the "near verification circle" if no one actually uses it to verify that the near power matches the etched number?

The reason for the circle in the lower half of a progressive lens is to verify there is indeed a circle there. If there is only a half circle or a little sliver, you've got problems.

[hcjilson]

Iam really enjoying this thread how the guys and gals are finding distorted parts on lenses that should not be so.

Maybe the lens companies should go back to the drawing board or drop the prices for these lenses until they can come up with something that will pass the lensometer test of a finished lens.

Has anybody found a clean undistorted reading pat yet ?

Chris, you really should try some of the newer lenses. DEFINITY is my favorite but there are other great designs. They are a vast improvement over the flat tops you told us you wear. :):):)
from your friend in codgerhood hj

[pseudonym]

The reason for the circle in the lower half of a progressive lens is to verify there is indeed a circle there. If there is only a half circle or a little sliver, you've got problems.

Ah so! That makes sense. I've seen several half circles in the shallow frames. Bet the person that wore those had to squint to read the paper.

[HarryChiling]

Ah so! That makes sense. I've seen several half circles in the shallow frames. Bet the person that wore those had to squint to read the paper.

Not really they'll just dip into their accommodative reserves more and have to purchase a new pair sooner.

[Chris Ryser]

Ah so! That makes sense. I've seen several half circles in the shallow frames. Bet the person that wore those had to squint to read the paper.

.................................or buy a magnifier. :bbg:

By having watched the threads on OptiBoard for years on the subject of progressives heights, I estimate there must be many millions of progressive lenses on peoples noses who pretend and try to read but have all the problems of doing so.

[chip anderson]

It's kind of like those who say they use all poly and never have any problems. Patient doesn't have anything to compare with unless he gets a pair this isn't poly. He thinks that's the standard. I see a great many people who have been sold glasses from all or near all poly dispensaries who get something non-poly from us with no change in Rx and exclaim: "I didn't realize I couldn't see with my old ones."

Chip

[pseudonym]

It's kind of like those who say they use all poly and never have any problems. Patient doesn't have anything to compare with unless he gets a pair this isn't poly."

Chip

If you mean polycarbonate, that's what I have and I love them. Varilux Comforts. What is better?

[hipoptical]

If you mean polycarbonate, that's what I have and I love them. Varilux Comforts. What is better?

Just about anything else.
Poly is terrible.
Varilux is hype- all marketing, zero new technology.
Higher Rxs usually notice the difference between poly and other materials more so than those with lower Rxs.
I know of at least 5 other lenses that I could fit you into, and you would notice no difference whatsoever compared to the Comfort. I know of several others that would perform better. I know of digital lenses that would cost the same (or less) than Comfort that would "wow" you, and some that cost more that would "wow" you. (And, yes, I know of others that are not as good, but like the Comfort, they are older designs.)

[hcjilson]

If you mean polycarbonate, that's what I have and I love them. Varilux Comforts. What is better?

DEFINITY'S in trivex!


Note to hipoptical- Varilux was revolutionary in 1994 in that it was the first "soft" design progressive, minimizing the swim effect of the unwanted astigmatism. Previous to that you had the VIP and the Varilux 2 which were hard designs and very unsat because of the blind spot on the periphery. It isn't just advertising that makes a lens a sucess.

[pseudonym]

DEFINITY'S in trivex!

You were just waiting for the opportunity, weren't you? I don't know enough about these lens materials yet to make an appraisal. Considering that I've had cars that didn't cost as much as the ones I wear now, "appraisal" is the only word that fits.

[hcjilson]

You were just waiting for the opportunity, weren't you? I don't know enough about these lens materials yet to make an appraisal. Considering that I've had cars that didn't cost as much as the ones I wear now, "appraisal" is the only word that fits.

You will notice I used that opportunity TWICE in this thread alone! :):)

[cvbs]

pseudonym, I only quickly scanned this topic and as to not being able to read the true add in the verify circle to match the engraved. This comes from to many "opticians" trying to fit progressives w/ longer intermediates into frames low seg hts. thus cutting off the add!!! If you use the "correct" lens for the frame the patient will get much better satisfaction out of the glasses and you will end up cutting down on remakes and keeping your costs in line besides. :cheers:

[pseudonym]

pseudonym, I only quickly scanned this topic and as to not being able to read the true add in the verify circle to match the engraved. This comes from to many "opticians" trying to fit progressives w/ longer intermediates into frames low seg hts. thus cutting off the add!!! If you use the "correct" lens for the frame the patient will get much better satisfaction out of the glasses and you will end up cutting down on remakes and keeping your costs in line besides. :cheers:

Who are these "opticians" of which you speak? (Scan the first post, I am only a student.)

So, you are the optician. A patient walks in who has made up her mind what frames she likes. Very opinionated lady, this patient. The frames are tiny and will not fit even your shortest corridor lens. She wants to keep the same progressive she's been wearing for the past 5 years anyway. You know this lens in those frames will rob her of her reading power.

Are you going to give the lady what she wants or are you going to kill the sale?

[hcjilson]

That answer is easy. When customers ask for something that you know is wrong, you don't do it. Forget progessives for a moment. What if the customer requests a couple of degrees of prism?..........You don't do that either, for the same reason. It's not on the Rx. If the customer asks for a frame that is too small for the progressive you could simply say, you can have them for distance, or you can have them for near, but you can't have them for both. You won't be killing a sale.....no one else would knowingly do the wrong because it will result in customer dissatisfaction.

[pseudonym]

You won't be killing a sale.....no one else would knowingly do the wrong because it will result in customer dissatisfaction.

They wouldn't? Cvbs has indicated the problem is "opticians" incompetence. Judging from the number of incomplete circles I've seen in the donation box, he may have a point.

Fashion is another problem. Could these tiny frames be tagged "no progressives" or will that just make the lady want them all the more?

[hipoptical]

DEFINITY'S in trivex!


Note to hipoptical- Varilux was revolutionary in 1994 in that it was the first "soft" design progressive, minimizing the swim effect of the unwanted astigmatism. Previous to that you had the VIP and the Varilux 2 which were hard designs and very unsat because of the blind spot on the periphery. It isn't just advertising that makes a lens a sucess.

I have never argued that Varilux is a bad product. The fact that a product was good at one time (compared to other products) does not mean that it's value stands for all time. If you were shopping for a computer, you would not buy from me a 1994 version when you could get a 2009 version for the same or less money, would you? The Varilux Comfort WAS a good lens in 1994. Compared to what you can get today, it is not. It is hype NOW... Varilux contracts with laboratories stated that the lab could not say anything was better than, as good as, or even compares to the Comfort. If it really is that good, then why write that language into a contract? It was hype that propelled the product, and hype that continues to sell it (combined with ignorance of "opticians"). Essilor is a marketing machine. They know they can't make anything outsell that lens now (notice I didn't say can't make anything better?) so they have to continue to sell old technology. Anyone willing to learn will find out quickly what the truth is, and they will sell better products and have happier customers. Everyone else will sell Comfort, and have "satisfied" customers. There are a lot of folks "satisfied" with their 1994 vehicles, there are happier people driving 2009 vehicles. Clothes, computers, TVs... we like everything upgraded, and updated, but we continue to sell 1994 eyeglasses????? NOT ME.

[OCP]

I have never argued that Varilux is a bad product. The fact that a product was good at one time (compared to other products) does not mean that it's value stands for all time. If you were shopping for a computer, you would not buy from me a 1994 version when you could get a 2009 version for the same or less money, would you? The Varilux Comfort WAS a good lens in 1994. Compared to what you can get today, it is not. It is hype NOW... Varilux contracts with laboratories stated that the lab could not say anything was better than, as good as, or even compares to the Comfort. If it really is that good, then why write that language into a contract? It was hype that propelled the product, and hype that continues to sell it (combined with ignorance of "opticians"). Essilor is a marketing machine. They know they can't make anything outsell that lens now (notice I didn't say can't make anything better?) so they have to continue to sell old technology. Anyone willing to learn will find out quickly what the truth is, and they will sell better products and have happier customers. Everyone else will sell Comfort, and have "satisfied" customers. There are a lot of folks "satisfied" with their 1994 vehicles, there are happier people driving 2009 vehicles. Clothes, computers, TVs... we like everything upgraded, and updated, but we continue to sell 1994 eyeglasses????? NOT ME.

I´m 100% agree in this.
Actually it´s one of the industries worst issues, to get the optician to order new and better products, and Varilux Comfort is the worst.
Why is it so difficult for Essilor to learn the opticians about better products.? Comfort is nothing than a old lens design with absolutly no optical characteristics, and the 360 is the same just stuff, just on the back surface. By introducing the Comfort on the back surface, Essilor will never get out of this vicious circle. Actually they admid they have done a bad information job here. They are shooting them self in their feet.