This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous, Subject name: Ophthalmology
[{'content': 'Maximum refraction occurs at \nSelect and explain. \nA. Anterior surface of cornea, B. Anterior surface of lens, C. Posterior surface of cornea, D. Posterior surface of lens', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. a (Anterior surface of cornea) (Ref: A K Khurana, 2nd/pg. 50, and Basak's Ophthalmology 2nd/pg. 4)Refractive mediumRefractive indexCornea1.38Aqueous humor1.33Lens1.4Vitreous humor1.34Air1Maximum refraction occurs at anterior surface of cornea because:1. Anterior surface of cornea has greater curvature and2. There is greater difference between refractive indices of air and cornea.Refractive surfaceRefractive PowerAnterior surface of cornea+48DPosterior Surface of cornea-4DLens of eye (Vivo)+15DLens of eye (taken out)+150D", 'role': 'assistant'}]