This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Errors of Refraction, Subject name: Ophthalmology
Most powerful refractory surface of eye is - 
Select and explain. 
A. Conjunctiva, B. Cornea, C. Vitreous, D. Lens
B: Cornea
Answer: B: Cornea 
Explanation: Ans. is 'b' i.e., Cornea o The cornea, with the anterior chamber and lens, refracts light, with the cornea accounting for approximately two- thirds of the eye's total optical power.o In humans, the refractive power of the cornea is approximately 43 dioptres.o The diopteric power of reduced eye is + 60D, of which + 44D is contributed by cornea and + 16D by the crystalline lens.o Total diaopteric power of schematic eye is + 58D, of which cornea contributes +43D and the lens +15D.