<prompt> Each layer of lens has a role in the refractive index of the entire lens. Which component has maximum refractive index?Anterior surface of the lensPosterior surface of the lensCentre of the lensCornea  <response>: Refractive index increases from 1.386 in the peripheral coex to 1.41 in the central nucleus of the lens. The anterior capsule surface of the lens has a greater refractive index than the posterior capsular surface 1.364-1.381 compared with 1.338-1.357. The change in refractive index from the surface of the lens to the center results from changes in protein concentration, the higher the concentration, the greater the refractive power. Ref: Ophthalmology edited by Myron Yanoff, Jay S. Duker, James J. Augsburger, 2009, Page 383. 