Abstract

Accurately modelling the refractive index gradient of the crystalline lens is essential in understanding the optical properties of the vertebrates visual system. A method of indirectly measuring the refractive index profile in intact crystalline lenses was devised by Campbell¹ (based on work² measuring refractive index profiles in optical fibers) and subsequently used by others to measure refractive index distributions in rat³, rock bass⁴, bovine⁵ and humans⁶. The total deviation of a set of parallel laser beams incident on the lens parallel to the optical axis or the equator are measured. For a spherically symmetric lens the index of refraction, n(r), at a distance r from the center of the lens can be calculated from the deviation angles, ψ(y), using the following set of equations, here ρ is the lens radius and y the perpendicular distance between a ray and the optical axis.

© 1992 Optical Society of America