What is the Difference?

[dioptical]

What is the difference between Conventional PAL, Multi-design PAL, Digital Surfacing PAL, free-form PAL, and wave front PAL?

Ginny

[xiaowei]

What is the difference between Conventional PAL, Multi-design PAL, Digital Surfacing PAL, free-form PAL, and wave front PAL?

Ginny

:finger:Hi dioptical, use the search function, these have been discussed at LENGTH,look up the papers I cited in the other thread, I just added another one from Essilor, Daryl has several papers on free-form, how it´s made etc. in the resources subdirectory

[au]

give a link

http://www.optiboard.com/forums/showthread.php?t=24739

hope his help !

:cheers:

[chip anderson]

About two hundred dollars, maybe three.

[finefocus]

conventional vs. multidesign - in the old days, there was one design regardless of base curve or add, so years ago "multidesign" came out - different design tradeoffs for different bases and adds

digital surfacing - ordinary surfacing using a grinding lap couldn't produce the complex curves you find on ordinary pal's, so they were molded on the front side, surfaced with ordinary spherical or toric curves on the back - now digital surfacing, or "point-polishing" enables grinding of those curves by grinding many data points on a surface and using soft, or deformable, polishing tools

wave front (a term stolen from LASIK) refers to fancy curves that compensate for higher order abberations - Essilor used the term, but inaccurately since their lenses like Physio 360 aren't wave front devices - Izon purports to use wave front-like measurements to "cure" their magic goo lenses, but at present I don't know of any true wave front eyeglass lenses

[Judy Canty]

My suggestion would be to invest in the latest edition of the System for Ophthalmic Dispensing by Brooks and Borish. The third edition has a pretty good section covering progressive lenses.

[HarryChiling]

This is a nice summary that shoud cover everything you need. I suggest you download and save it, then please share it with your collegues.

http://www.varilux-university.org/E_...OO-PROG-UK.pdf

[Fezz]

Thanks Harry. Great link!!

[Ginster]

Thanks Harry, this is excellent..


Ginny :)

[optifocus]

This is a nice summary that shoud cover everything you need. I suggest you download and save it, then please share it with your collegues.

http://www.varilux-university.org/E_...OO-PROG-UK.pdf

Nice links harry thanks for sharing.

[HarryChiling]

:finger:Hi dioptical, use the search function, these have been discussed at LENGTH,look up the papers I cited in the other thread, I just added another one from Essilor, Daryl has several papers on free-form, how it´s made etc. in the resources subdirectory

xiaowei I didn't mean to steal you thunder here man, I just realized that you did have the essilor article on another thread. I didn't see that when I posted here, but you did have it up and it is a rgeat resource kudos to you. They use to also have Mo Jalies CD's on their and you could juts give them your info and they would mail you a copy of three of his CDs free, but they removed that part and now the NAO is selling at least one of the CDs fro some exhorbitent amount. First come first serve as they say.

[xiaowei]

xiaowei I didn't mean to steal you thunder here man, I just realized that you did have the essilor article on another thread. I didn't see that when I posted here, but you did have it up and it is a rgeat resource kudos to you. They use to also have Mo Jalies CD's on their and you could juts give them your info and they would mail you a copy of three of his CDs free, but they removed that part and now the NAO is selling at least one of the CDs fro some exhorbitent amount. First come first serve as they say.

Harry, no problemo, I was not totally clear in my post, as I wrote about "the other thread", which seemed obvious to me in that moment, because I actually adressed "dioptical" who had just started both threads on basically the same subject!!

:cheers: