This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Ophthalmology
[{'content': 'Which is not a cause for Hamarlopia? \nSelect and explain. \nA. Polar cataract, B. Congenital deficiency of cones, C. Peripheral coical cataract, D. Central corneal opacity', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Peripheral coical cataract causes Nyctalopia. Central vitreous opacity, Congenital deficiency of cones and Central nuclear or polar cataracts can cause Hamarlopia (Day blindness). Ref: A K Khurana, 2nd Edition, Page 11.', 'role': 'assistant'}]