This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Optics and refraction, Subject name: Ophthalmology
Refractive index of cornea is - 
Select and explain. 
A. 1.33, B. 1.37, C. 1.42, D. 1.45
B: 1.37
Answer: B: 1.37 
Explanation: The refractive index is 1.376. Reference: Parson&;s 21st edition page51