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': 'Coloured halos are seen in all, except – \nSelect and explain. \nA. Cataract, B. Angle closure glaucoma, C. Corneal edema, D. Corneal opacity', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Causes of coloured halos\n\nCorneal edema\nGlaucoma (elevated IOT)\nClosed-angle glaucoma\nOpen-angle glaucoma\nEarly stages of cataract\nToo intense exposure to light (snow blindness)\nVitreous opacities :- hemorrhage, asteroid bodies\nAsymmetric placement of intraocular lens\nMucopurulent conjunctivitis\nEpiphora\nHypoglycemia\nMyopia\nForeign body\nDrugs\nCorticosteroids\nAmiodarone\nDigoxin\nChloroquine\nOCPs', 'role': 'assistant'}]