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': 'All are true about keratoconus except: \nSelect and explain. \nA. Increased curvature of cornea, B. Astigmatism, C. K.F. ring cornea, D. Thick cornea', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. Thick cornea', 'role': 'assistant'}]