It's very complicated to calculate base curve when you know your prescription.
Type: Posts; User: Emily Chen; Keyword(s):
It's very complicated to calculate base curve when you know your prescription.
Thank you, I still try to calculate the cutted lens edge thickness for plus and minus lens. It's hard to do it,thanks
If I use this formula to calculate centre thickness of plus lens, how calculate the thickness of cutted edge ? any one could help me?
Sagitta = R - √(R^2 - (D / 2)^2)
C.T. = S1 + E.T. - S2 (for plus lenses)
E.T. = S2 + C.T. - S1 (for minus lenses)
E.T. = edge thickness (in mm)
C.T. = center thickness (in mm) ...
Great! thank you for your share:bounce:
I try to make one formula for Calculating the cutted lens Edge thickness. and Made one according to Spex and Darry forum. But I find that the formula are correct for negtive lens, but not for...
Hi Darry
Do your formula for both Positive and Negtive lens?