This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cornea, Subject name: Ophthalmology
According to biophysics, in which pa of eye does maximum refraction occur? 
Select and explain. 
A. Cornea, B. Aqueous humor, C. Centre of the lens, D. Periphery of the lens
A: Cornea
Answer: A: Cornea 
Explanation: Cornea The cornea is the first and most powerful refracting surface of the eye. Light passes through the transparent cornea on its way to the retina. It has a greater curvature than the rest of the eyeball and a refractive power of approximately 44 dioptres.