The lens maker’s formula involves the focal length, refractive index of the material of the lens and the radius of curvature of the two surfaces of the lens. This formula is derived from the refraction of light
Lens Maker Formula for Concave Lens and Convex Lens For a concave lens, R1 is negative and R2 is positive. The lens maker formula for the concave lens is given by, \[\frac{1}{f}=-(\frac{\mu _1}{\mu _2}-1)(\frac{1}{R_1}+\frac{1}{R_2})\] ...