<prompt> Most impoant factor in the convergence of light rays on the retina isLength of eye ballDioptre power of lensCentre of lensCornea  <response>: The total dioptric power of the eye is about 60 D out of which about 44 D is contributed by the cornea and 16 D by the crystalline lens. The human eye is spherical and its internal pas are transparent so that the maximum amount of light can reach the retina. The cornea surrounds and protects the eye. It is made of transparent gel-like material that helps converge light rays onto the retina. Khurana 4e pg: 26 