Does anyone know if Dr Sheedy is going to come out with another progressive study? I would be curious to see how the new prog stack up, especially freeform.
Does anyone know if Dr Sheedy is going to come out with another progressive study? I would be curious to see how the new prog stack up, especially freeform.
I for one would prefer to see data produced from someone like COLTS Laboratories www.colts-laboratories.com/ Colts has the equipment and experience to conduct such a study! Of course it would cost, and who would pay for this? If it was funded by the lens manufactures they would own the test data, they wouldn’t release the results if their product turned out poorly.
In one of the past studies, products from several of the larger manufactures (that didn’t fund the effort) were ranked kinda “so so” or not even included while products from companies funding the study did a little bit better! Perhaps the "so so" rated products were really "so so", or perhaps $$ had something to do with the results. The conclusions reached were interesting, but the result were based on limited test data.
So what are we to do??
Consumer Reports comes to mind as an independent testing agent. Anyone know anyone associated with them?
I'd like to slip 2 of the same brand lenses into the same test batch and see how many "see" a difference between the same lens!;)
Good thought!!
I doubt if Consumers Union has the knowledge to do the extensive testing required for this kind of study. Of course they could partner with someone (like Colts or others) for assistance.
but…
I could think of nothing worse than having study information getting out to the public. We’d have patients demanding a given brand based on their limited understanding of such a report. It is the responsibility of the eye care professional to understand the patient’s needs and to prescribe the best lens design or product to fulfill those needs.
Many lenses manufacturer don't like many reports of Dr.Sheedy , but Advance Progressive Addition Lenses Club love his report so much.
Cheer to Dr.Sheedy!
:cheers:
Last edited by Bobie; 09-17-2008 at 07:22 AM.
" Life is too short to limit your vision"
ISOPTIK : The Hi-End Eyeglasses Centre
494 ERAWAN BANGKOK 4th floor
Ratchaprasong , Bangkok , Thailand 10330
isoptik@gmail.com
www.isoptik.com
Hotline & SMS : +66 81 538-4200
Fax. : +66 2 251-3770
:cheers:
Ditto.
: )
Laurie
Science is a way of trying not to fool yourself. - Richard P. Feynman
Experience is the hardest teacher. She gives the test before the lesson.
Hello,
Dr. Sheedy used the exact same equipment that John Young from Colts uses: The Rotlex Class One System. The results would likely be the same.
There are a handful of them around the country, and Dr. Sheedy used it when he conducted the study (in Ohio Optometry School, if I remember correctly)...they own a Rotlex Class One.
And, without a doubt, he did not get paid by lens manufacturers to conduct this study...it was completely non-biased. Lens manufacturers did not even know the study was being conducted until it went to print.
I suspect that Bobie also uses the Rotlex system...is this correct Bobie?
: )
Laurie
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We used Rotlex system , because I follow procedure of Dr.Sheedy. :bbg:
" Life is too short to limit your vision"
ISOPTIK : The Hi-End Eyeglasses Centre
494 ERAWAN BANGKOK 4th floor
Ratchaprasong , Bangkok , Thailand 10330
isoptik@gmail.com
www.isoptik.com
Hotline & SMS : +66 81 538-4200
Fax. : +66 2 251-3770
:cheers:
From my acquaintance with Dr. Sheedy this is exactly the type of an academic researcher we all would like to see in terms of professionalism and ethical conduct.
As for the equipment, both Colts and Sheedy use similar Rotlex mapping devices. However, Sheedy's one is a new-generation instrument.
I have always been curious how particular designs would behave in combination with oblique astigmatism, with the rule, and against the rule. I would think certain designs would be terrible for certain scenarios and it would be nice to have access to a compiled database of maps showing the designs and their characteristics combined with the different scenarios.
Also it would be nice to have a set standard developed for increments, colors used, and various other parameters on these maps so that the individual lenses can be compared easier.
I started about a year ago purchaseing right lenses of a few different progessives and have surfaced the following Rx's into them:
Plano Add+2.00
Plano -1.00 x 180 Add +2.00 (WTR)
Plano -1.00 x 090 Add +2.00 (ATR)
Plano -1.00 x 045 Add +2.00 (Axis running the nasal side of the design)
Plano -1.00 x 135 Add +2.00 (Axis running the temporal side of the design)
The hopes was to find someone to map them and provide that data for any opticians to use. Only one company provided me with blanks the rest I have bought and it has been a significant investment. I don't have enough resources to pay to have them mapped or enough resources to purchase a proper sample size.
Bobie,
I would be more than willing to mail you the lenses if you map them?
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For years, I’ve been offering Eye care professionals like you, to map lenses using the state-of-the-art equipment in my lab. I stress that as long as the number doesn’t exceed 20 per week, I can do this free-of-chege. So far, I've received nothing from this forum, although I continuously receive such lenses from existing and potential customers.
Anyway, I'll be glad to map your lenses (free-of-charge), and return them along with their matching maps and a viewer software which will enable you to analyze them.
My address is:
Raanan Bavli
Rotlex
Unit 2D,
Omer Industrial Park.
Omer,
Israel, 84965
Last edited by Raanan Bavli; 06-07-2008 at 03:37 AM.
that I think I'm seeing undo emphasis placed an too many technical parameters of progressive lens design. Missing from this pot-o-gold is:
1. the accuracy and efficacy of the starting Rx.
2. an understanding that NONE of these parameters have yet been analyzed or correlated with client perceptual adaptations.
Just one anecdotal example:
Varilux comfort, a 14 year old traditional soft design, continues to prove an "acceptable-to-excellent" lens for most clients, at a reasonable cost.
The value of *any* progressive analysis, to me, will be to tell me why this is so, compared with other designs.
I had a client that digested the Sheedy study here on optiboard, founds me, travelled out from Mahattan, and decided he wanted Genesis on the basis of the study. I recommended Comfort. He asked (and paid for, with a reduction in price) two identical sets in identical frames.
His conclusion:
[I was "right"(?!)]; He liked Comfort better.
When a parametrical analysis helps me to understand why my ancedotal experience is this way, *then* I'm interested. Otherwise, its all the same type of "objective" approach to lenses that I feel misplaces emphasis on optical parameters we understand, versus those psycho-perceptual ones that we yet don't.
FWIW
Barry
Barry,
Of course you are right when saying (though indirectly) that the wearer's test is more important than all features weighed in any analyis. However, everyone knows that each wearer has different viewing habits. I don't remember how Sheedy refered to this issue, but it's clear to me that the reason that there are so many designs in the market relates to the fact that there are several classes of wearers.
So, when comparing the user's response to these lenses, we need to consider the characteristics of this user (much more difficult than mapping and analyzing lenses).
The last (Varilux sponsored) "education" class I attended. Varilux said that the comfort was the best PAL design ever created (including all thier own). The word "Panamic" was not mentioned in the course except when brought up by the audience. Varilux when discussing all it's latest and greatest inovations has said that they are improvements or modifications of the comfort design.
Not too sure I would disagree with them on this. Although I have had little difficulty when changing patients from PAL designs and brands, I can recall very few problems when comforts were used as first time, replacements, or intentional changes.
Chip
Hi, Harry Chilinguerian
Your concept is good to plot each design of semi-finished PALs from
Plano Add+2.00
Plano -1.00 x 180 Add +2.00 (WTR)
Plano -1.00 x 090 Add +2.00 (ATR)
Plano -1.00 x 045 Add +2.00 (Axis running the nasal side of the design)
Plano -1.00 x 135 Add +2.00 (Axis running the temporal side of the design)
After we have plotted a lot of expensive semi-finished PALs and compared with a lot of free form PALs. We've found out that we can not trust information from PALs company anymore and we never recommended any semi-finished PALs to our customer anymore.
Normally , we have been using all data we plot for our member only and will open for worldwide on 2010.
:cheers:
Last edited by Bobie; 09-17-2008 at 07:24 AM.
" Life is too short to limit your vision"
ISOPTIK : The Hi-End Eyeglasses Centre
494 ERAWAN BANGKOK 4th floor
Ratchaprasong , Bangkok , Thailand 10330
isoptik@gmail.com
www.isoptik.com
Hotline & SMS : +66 81 538-4200
Fax. : +66 2 251-3770
:cheers:
Please , read this article and you will understand that , why the PALs Empire don't like Dr.Sheedy.
:D
Progressive addition lenses—measurements and ratingsJim Sheedy, O.D., Ph.D.*, Raymond F. Hardy, B.S., and John R. Hayes, Ph.D.
http://optometry.osu.edu/COOR/pdfs/p...AOA_paper2.pdf
Last edited by Bobie; 09-17-2008 at 07:24 AM.
" Life is too short to limit your vision"
ISOPTIK : The Hi-End Eyeglasses Centre
494 ERAWAN BANGKOK 4th floor
Ratchaprasong , Bangkok , Thailand 10330
isoptik@gmail.com
www.isoptik.com
Hotline & SMS : +66 81 538-4200
Fax. : +66 2 251-3770
:cheers:
Although Dr. Sheedy's papers on progressive designs are to be commended, they are not studies on user preference. Although this is harder to achieve it should be done. Here are some of the problems:
-All the fittings need to be standardized. This would have to be done by an academic center or some other venue in which profit is not a motive. The fittings would need to be done by a controlled group of highly trained opticians who follow rigid guidelines.
-The different groups that are fit would need to be controlled as to age, degree of presbyopia and prescription ie: young myopes between -1.00 and -3.00 with no more than 1.75 diopters of presbyopia.
-The populations would need to be randomized to various PAL designs.
-The study would need to be double blind ie: neither the fitter not the patient knows what designs they are getting.
-All confounding variables need to be removed ie: PD errors, base curve errors, prescription errors, materials differences etc. This would require very rigid quality control at all levels.
-The subjects would then need to be polled at 3 months, 6 months and one year with a questionnaire that assesses all levels of optical use of their PAL's.
Only a study of this design would come remotely close to answering the questions that we are all asking
That sounds crazy expensive and we still can't rule out posture and height and habits of people. If we fit every individual in each one of the designs then used their responses maybe but it's not necessarily feasable. The Sheedy study is amazing not for tellign us which lenses to fit on which patients but for giving us an idea of how the lenses are desinged.
No manufacturer want's to admit the area of the design they sacrificed to improve another so when one says we have the widest XXXX I would like to know where the sacrifice came from? Did they narrow the XXXX, or have a higeher amount of XXXX in the periphery of the lens. The Sheedy study gives us a rating system to use on progressives and groups lenses by their strengths and weaknesses, I don't think even the manufacturers and desingers will claim to know how to fit every patient in the exact lens design that would be optimal for the patient, not unless we detach the eye's from the brain and hook it up to a standardized computer. Just my opinions.
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This study and others, while interesting and of some value are somewhat akin to measuring a fart. No standards exist for procedures and no standards exist for numerical values. There are many unknown variables on the input side of the equation; it's a classic case of garbage in - garbage out.
I am of the belief that we practice in an age where most modern progressives work fine. Sure, there are subtle differences, but it doesn't seem to matter.
Search your soul, search your pocketbook, search for what works for you!
Find a progressive or three that cover almost every material, fitting height, patient profile and go for it!
Image is a good place to start (except for those blasted markings-no missing them!).
:cheers::cheers::cheers::cheers:
Almost but not exactly, it's not garbage in although it could be argued as garbage out. I don't know if we will ever come up with a standard that we could apply to the adaption or satisfaction of patients and PALs. If lenses were mapped at teh least we would be able to come up with our own marketing garbage instead of relying on what's spoon feed to us. I have a lot of literature that displays iso maps on them, yet every manufacturer and person here says the same thing the maps are useless, but the manufactureres are using them and the mareting departments are using them, even if for no other reason than to have a great illustration to improve the patients perception of the design they can be usefull in the hads of a competent optician. Same with the rating system devised by Sheedy, the entire paper read from front to back to me gave a great description for an objective measure of the lenses.
There will never be any piece of equipment that can measure such a subjective thing as adaption or satisfaction and the numerous attempts here to ask many opticians to even factor in cost to the equation has only lead to me beign called cheap or frugal. There are those who have no understanding of the lenses that they ft but if the same manufacturere came out with a more expensive version they would just assume the higher price tag meant better. Now better can be defined as more distance, reading, or intermediate area. Or higher Sheedy rating for a progressive factoring astigmatism for distance and intermediate. Now we can start to make progress towards quantifying better.
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