lens thickness formula

[Optom]

David,
All explanations are good and I will sit with opticians at my office to further learn dispensing optics.
A good reason to join you folks.
Thanks again dear all.

[Alan W]

You guys . . . . are so smart. It scares me. I mean . . where did all this smart come from? It sure ain't on the general forum!
Now, I'm just a country boy with a degree here and there . . . but I always used a simple rule of thumb for the ED. Until recently I considered ED to be Estimated Diagonal measurement with the understanding that it would with only a couple exceptions, be the longest measurement of a lens. A hypotenuse of sorts. However, in modern times ED now seems to be confused with . . . nahhh . . . I won't say it!
Ask Bob Dole!

[CJ Engel]

I agree with David on this subject. You are 100% spot on with every statement you made here David. That’s probable the reason you are in Charge of training of half the good Opticians out there. Good work David.

As far as the VARIFOCAL’S I would agree that it originated from the VARILUX brand. Essilor runs the Varilux University and just for the record in their entire fitting guide for fit VARILUX lenses they refer to them as (PROGRESSIVE LENSES). So I am guessing that the internationally recognised term (PROGRESSIVE LENS) now speaks for itself. In South-Africa the majority of us use the “progressive” term. Maybe one or two very old optoms will use multifocal or varifocal. Maybe its an age related thing Maria? =)

Regards
CJ

[Speed]

Most formulas calculate for 0 ct or et. Make sure you are adding those somewhere.

[Fezz]

****9 year old thread revival ALERT****