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QDO1
09-19-2005, 10:19 AM
Is there a source of standardised PPL lens data, across the brands, that alows a side by side comparison of the physical aspects of the lens? It strikes me we all have our favourites, but dispensing choices are based on gut-feeling / brand loyalty or just good experience, as opposed to a scientific ananysis of the task infront of us

the data I would like at my fingertips could include for example:


Progression width at 5, 10, 15, 20 mm below fitting cross
Progression power at 5, 10, 15, 20 mm below fitting cross
Measurement at which full reading power is achieved
Above 180 distortion patterns / power error %

The problem as we all know, is that each manufacturers literature does naturally "slap some gloss" on thier particular lens design, leaving the optical professional with a pile of lens sheets all professing to be the best thing since...

People may finish that sentance as they see fit

Jedi
09-19-2005, 10:56 PM
Try searching for Dr. Sheedy on this site, I believe there is a link to his study of progressives. It doesn't covering everything, but I find it a good resource.

rinselberg
09-20-2005, 02:39 AM
Try searching for Dr. Sheedy on this site, I believe there is a link to his study of progressives. It doesn't covering everything, but I find it a good resource.You can find links to two of Dr. Sheedy's publications on this web page:
http://optometry.osu.edu/COOR/4059.cfm

Thanks to OptiBoarder Robert Martellaro
http://www.optiboard.com/forums/showpost.php?p=101391&postcount=14

QDO1
09-20-2005, 08:24 AM
Wow.. now that is a facinating read. Dr Sheddy certainly has opened up a can of worms. Very useful information. ThanksDo any of you guys use Nikon in The US? what results do you get?