State the surface powers required to produce the following lenses with +6.25D front curves.
a. -0.50 DS
b. +0.50 DS
c. +1.75 DS
Is a= -6.75D?
b= -5.75D?
c= -4.75D?
To calculate the required surface powers, you need to use the lens formula:
P = (n2 - n1) / r
Where:
P: Surface power (in diopters)
n2: Refractive index of the lens material
n1: Refractive index of the medium surrounding the lens
r: Radius of curvature of the lens surface (in meters)
For all of the following calculations, I will assume that the refractive index of the lens material (n2) is 1.5 and the refractive index of the medium surrounding the lens (n1) is 1.0.
a. To find the required surface power for -0.50 DS lens:
P = (1.5 - 1.0) / (-6.75)
P ≈ -0.0741 D
b. To find the required surface power for +0.50 DS lens:
P = (1.5 - 1.0) / (-5.75)
P ≈ -0.0869 D
c. To find the required surface power for +1.75 DS lens:
P = (1.5 - 1.0) / (-4.75)
P ≈ -0.1053 D
Based on the calculations, it appears that the values you provided for a, b, and c are incorrect. The correct values would be:
a. -6.75 D
b. -5.75 D
c. -4.75 D