POW compensation for digital progressives a la Zeiss Individual

[OCP]

You sound more and more like one that are selling expensive equipment to take all the worlds unimportant measures.
Let me refresh your memory to use the right contributions from me.

I said from the beginning that Pantoscopic was not a fixed value and nearly impossible to measure prober, so I suggest to use ex. three standard measures like 5-10-15 and consider this visual. Everyone called me an idiot and try in different ways to explain me, that this was for sure an fixed value. Now we know that Pantoscopic is an average, and therefor not an fixed value (Still everyone call me an idiot and thats okay with me. hahahaha).

I said that Vertex was impossible to measure prober, because no one here can do it correct and the power only change minor below 5D. One simple issue is, how do you mount the lens in the frame? That can easily change the vertex 3 mm. You claim that ½ mm vertex was so, and so important. How can can you claim such a ridicules thing?

I know your selling a very expensive Infral to take unimportant measures, but telling lies in this forum and get respect and honour for this................. I could vomit. (sorry my Frensh).

[Darryl Meister]

You sound more and more like one that are selling expensive equipment to take all the worlds unimportant measures.

I do not use OptiBoard as a promotional vehicle for my company's goods or services. Nor do I condone such behavior by others, which is why I often take issue with many of your posts.

As for "selling expensive equipment," Carl Zeiss Vision makes a free tool available to eyecare professionals to take position of wear measurements. As does Shamir.

Everyone called me an idiot

Despite your inveitable insults, and the fact that you deliberately ignore every point anyone ever makes in these threads, I certainly haven't called you an idiot.

Now we know that Pantoscopic is an average, and therefor not an fixed value (Still everyone call me an idiot and thats okay with me. hahahaha).

I see that once again you have ignored everything in these posts.

the power only change minor below 5D.

And you are once again confusing power compensation with optical optimization.

I know your selling a very expensive Infral to take unimportant measures

Actually, you are the only one who has mentioned the Infral system.

, but telling lies in this forum and get respect and honour for this................. I could vomit.

The truly scary part is, you're probably serious.

[mahmoud.hamza]

We are not in a ware

try to be more objective and I am sûre that you and all others will well understand every thing

can some one give us a real definition Of the "power compensation " and the optical optimization"
from that we can fix a subject and reach the target :)

[NewTop]

Sorry Mike, I have to agree with Darryl here.

"power compensation" is the differance in power between vertex distance at refraction and vertex distance with the frame. In contacts this is very important, a refraction of -3.00 at 12mm gives a (soft)contact of -2.75.

"the optical optimization" keeping it very basic, if the vertex distance with the frame is larger you need a softer design or more a-spherical in single vision.

Vertex distance at refraction, everage aprox 12 mm and can be easily measured at any phoropter.
Vertex distance with the frame, not very easy to measure and a bit variable.

Mike has a point when he says that not everone can measure vertex and and tilt properly.

Regards,

John (allso a reseller of Shamir in Europe)

[OCP]

Hi Newtop.
Nice to hear from you.

If you measure the refracted Vertex to 14 and the fitted Vertex to 12 in 3D you will maximum get a difference of aprox. 0.01D so absolutely nothing noticeable difference.
When you say everyone can easily measure the Vertex in a phoropthor your wrong. It´s so impossible that 3 people would get different measures, and to measure the Vertex in a frame with out knowing anything about how the lens will be mounted in the frame is just as precise as guessing on the lottery number.
It´s all about average values and guesswork.

Your right about the optical optimazation and how we can use the Pantoscopic and the Vertex values. I dont disagree, but if we cant measure these NON fixed values prober anyway you can just as well using standard values.

The US boys here have no problem measure Panto and Vertex, because in the US these values are 100 % fixed and very easy to measure. In Europe it´s not. WHY? Are we so different in Europe, or are the Americans really so special??

[NewTop]

If you measure the refracted Vertex to 14 and the fitted Vertex to 12 in 3D you will maximum get a difference of aprox. 0.01D so absolutely nothing noticeable difference.

Correct, thats power compensation. If you talk about optical compensation you're not correct. A vertex in the frame of 14 gives you a softer FreeFrame lens than a vertex in the frame of 12 in the same power.

When you say everyone can easily measure the Vertex in a phoropthor your wrong.

No I'm not, have you seen the vertex measurement prisms on the temporal side of most phoropters?

to measure the Vertex in a frame with out knowing anything about how the lens will be mounted in the frame is just as precise as guessing on the lottery number.

Your right, so if this is measured in a wrong way or mounted in the wrong way you won't get a perfect lens just a good lens. But there are opticians who know what they are doing.

The US boys here have no problem measure Panto and Vertex, because in the US these values are 100 % fixed and very easy to measure.

Pantoscopic tilt is just as variable as fittingheight and you measure it in the same position as you measure the fittingheight.

[OCP]

Correct, thats power compensation. If you talk about optical compensation you're not correct. A vertex of 14 gives you a softer FreeFrame lens than a vertex of 12 in the same power.



No I'm not, have you seen the vertex measurement prisms on the temporal side of most phoropters?



Your right, so if this is measured in a wrong way or mounted in the wrong way you won't get a perfect lens just a good lens. But there are opticians who know what they are doing.




Pantoscopic tilt is just as variable as fittingheight and you measure it in the same position as you measure the fittingheight.

My biggest problem here on this forum is to explain my self prober enough. If I could only explain in danish it would be much more easy.

To build an individual lens 100 % perfect, I think this is what we want to everyone, we need 100 % accurate measures, right?
We dont want any source of errors.
We can only measure the Pantoscopic tilt right here and right now, without taking the clients real life head position in consiteration.
We can only measure the refracted and the fitted vertex right here and now, without taking the mounting of the lens in the frame in consiteration.
I know all this very well and we cant disagree about this.

BUT what will you win in the end of the day, if these values only give a minor effect anyway, and so many source of errors?
You can win a little bit of design compensating (if you measure 100% correct) and a little bit of power compensating if you measure 100 % correct.
BUT what if you ½ the times measure a little bit incorrect? All in all it´s not a question about taking these irrelevant measures.

We have made a very small investigation with a few clients in Denmark.
We put them in similar powers with Autograph II with hypothetical Panto and Vertex and with fixed Vertex and Panto. (Panto 5 degree from measured, Vertex 3 mm from measured)
So far NO one could feel any difference at all.

This strength my believe that this is more a market gimmick than this gives any noticeable improvement.

[NewTop]

My biggest problem here on this forum is to explain my self prober enough. If I could only explain in danish it would be much more easy.

The same here but in Dutch:)

To build an individual lens 100 % perfect, I think this is what we want to everyone, we need 100 % accurate measures, right?
We dont want any source of errors.

If you try to aproch perfection you have to measure these difficult values.

We can only measure the Pantoscopic tilt right here and right now, without taking the clients real life head position in consiteration.

You can say the same thing about fitting height.

We can only measure the refracted and the fitted vertex right here and now

We can only measure the power right here and right now. The vertex at refraction is fixed and lasts for 15 minutes.

without taking the mounting of the lens in the frame in consiteration.
I know all this very well and we cant disagree about this.

Agreed

BUT what will you win in the end of the day, if these values only give a minor effect anyway, and so many source of errors?

Source of errors?
Lets say I have a client with a very large nose, he has a frame vertex of 16mm. What would be the best choice:

A) Autograph PLUS
B) Autograph FreeFrame ( I give a frame vertex of 14, everyone can notice that the frame is a bit far away from the eyes)

You can win a little bit of design compensating (if you measure 100% correct) and a little bit of power compensating if you measure 100 % correct.
BUT what if you ½ the times measure a little bit incorrect? All in all it´s not a question about taking these irrelevant measures.

The measurements are not irrelevant, its irrelevant to sell a compensated lens to an average person with an average frame. A client couldn't tell the differance from a PLUS to a FreeFrame if all the "special" values are average and the fittingheight is 14, 16 or 18.

[Darryl Meister]

can some one give us a real definition Of the "power compensation " and the optical optimization"

NewTop touched upon the differences. I also have a few articles on the subjective available for download from the OptiBoard File directory that you might find useful, including Progress in the Spectacle Correction of Presbyopia, a two-part series published in Clinical & Experimental Optometry.

Prescription compensation simply refers to any deliberate changes to the original prescription at the distance and near measurements points of the lens. When a lens is tilted or displaced, the prescription of the lens effectively changes. It is possible to "compensate" the original prescription for this effect when there is a significant difference between the orientation of the fitted spectacle lenses and the trial-frame or refractor-head lenses used to determine the initial correction. This commonly applied to certain free-form lenses and even to semi-finished lenses in "wrap" frames or of high power.

Optical optimization, on the other hand, refers to changes made to the actual lens design. When optimizing modern progressive lenses, the position of the fitted lens is utilized to "ray trace" the optical performance of the lens-eye system for various points over the lens. Since the position of the lens dictates the viewing angles and distances required to see through any given point on the lens, the lens position significantly influences the ray-traced power calculations and, hence, the optics of the lens design. It is therefore possible to "dial in" the wearer's specific position of wear in order to recalculate the optics of the lens design appropriately.

Mike has a point when he says that not everone can measure vertex and and tilt properly

I agree that this angle is difficult for some eyecare professionals to measure properly, at least without sufficient training. However, that doesn't make this measurement any less important. Prior to the widespread use of manual-focusing focimeters, lens power was difficult to measure as well. But few would argue against its importance.

And I agree that some wearers may replace their eyeglasses in slightly different positions on occasion, particularly if the eyeglasses have not been adjusted properly. Mike has been mistakenly associating normal changes in head tilt with changes in pantoscopic angle, however. Pantoscopic tilt does not change as the wearer raises or lowers his or her head.

John, I agree with virtually all of your comments. Although I would be genuinely surprised if the lens designers at Shamir actually supported many of Mike's statements, I think your posts reflect very positively on Shamir.

Are we so different in Europe, or are the Americans really so special??

Actually, measuring and supplying the pantoscopic tilt angle was first pioneered in Europe ten years ago. The first-generation Individual design used this measurement when it was launched in 2000. I believe that Rodenstock also accepted certain position of wear measurements rather early on for their Multigressiv lenses.

We have made a very small investigation with a few clients in Denmark... So far NO one could feel any difference at all

The University of California at Berkeley's Clinical Research Center conducted a randomized, double-masked study of 100 wearers comparing Zeiss Individual to traditional progressive lenses, and the study yielded a statistically significant preference for Zeiss Individual. The results will be published in a peer-reviewed journal very soon.

[Steve Machol]

You sound more and more like one that are selling expensive equipment to take all the worlds unimportant measures.
Let me refresh your memory to use the right contributions from me.

I said from the beginning that Pantoscopic was not a fixed value and nearly impossible to measure prober, so I suggest to use ex. three standard measures like 5-10-15 and consider this visual. Everyone called me an idiot and try in different ways to explain me, that this was for sure an fixed value. Now we know that Pantoscopic is an average, and therefor not an fixed value (Still everyone call me an idiot and thats okay with me. hahahaha).

I said that Vertex was impossible to measure prober, because no one here can do it correct and the power only change minor below 5D. One simple issue is, how do you mount the lens in the frame? That can easily change the vertex 3 mm. You claim that ½ mm vertex was so, and so important. How can can you claim such a ridicules thing?

I know your selling a very expensive Infral to take unimportant measures, but telling lies in this forum and get respect and honour for this................. I could vomit. (sorry my Frensh).

Your derogatory posts and language are simply not acceptable on OptiBoard. If you cannot act professionally and maturely, then find another playground to play in. This conduct will no longer be tolerated.

Everyone can personally thank OCP (hiding behind a pseudonym) for this thread being closed.