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': 'Refractive power of eye can be changed by: \nSelect and explain. \nA. Radial keratotomy, B. Keratomileusis, C. IOL, D. All', 'role': 'user'}, {'content': 'Answer: D \nExplanation: A i.e. Radial keratotomy; B i.e Keratomileusis; C i.e. IOL', 'role': 'assistant'}]