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': 'Most common cause diminision of vision in Peterygium is \nSelect and explain. \nA. Obstruction of visual axis, B. Corneal perforation, C. Myopia, D. Astigmatism', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Most common cause of diminision of vision in Peterygium is Astigmatism.', 'role': 'assistant'}]