This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diseases of Cornea, Subject name: Ophthalmology
[{'content': 'Most common type of astigmatism in keratoconus is \nSelect and explain. \nA. Simple myopia, B. Simple hypermetropia, C. Irregular astigmatism, D. Regular astigmatism', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Keratoconus usually have irregular astigmatism * B/L Non inflammatory ectatic condition of cornea Clinical Presentation * Young females with constantly changing power of glasses with myopia & high cylinder and irregular astigmatism SIGNS IN KERATOCONUS Munson sign Enlarged corneal nerves Oil droplet reflex( on DDO) Rizutti sign Hydrops Fleischer ring', 'role': 'assistant'}]