This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Elementary Optics, Subject name: Ophthalmology
Most important factor determining convergence of light rays on the retina is : 
Select and explain. 
A. Length of the eyeball, B. Refractive power of the lens, C. Curvature of the cornea, D. Physical state of the vitreous
C: Curvature of the cornea
Answer: C: Curvature of the cornea 
Explanation: Ans. (c) Curvature of the corneaRef: Optics of the human eye, p. 15-20Cornea is the most important refracting medium responsible for convergence of light rays to the retina because of its curvature and difference in refractive index from air to cornea.