Medical physics

Question

A spectacle maker wants to make a lens with a power of 3 diopters from a material with a refractive index of 1.5; After cutting, what is the radius of each side? (Suppose two surfaces of a lens have the same radius)

 

Answer 1

1/F = ( µ - 1 ) (1/R1 -1/R2 )

F = Focal length , µ = Refractive index , R1 = Radius of curvature of side left, R2 = Radius of Curvature of right

R1 = -R2 = R

Power = 1/F

1/P = (µ -1) ( 2/R) = 3 = (1.5 -1)(2/R) = 0.5*2/R

3 = 1/R

R = 1/3 m = 100/3 cm = radius curvature of each side