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
Which is not a cause for Hamarlopia? 
Select and explain. 
A. Polar cataract, B. Congenital deficiency of cones, C. Peripheral coical cataract, D. Central corneal opacity
C: Peripheral coical cataract
Answer: C: Peripheral coical cataract 
Explanation: 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.