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': 'Methyl alcohol causes blindness by affecting which of the following structures? \nSelect and explain. \nA. Retinal ganglion cells, B. Nerve fibers, C. Rods & Cones, D. Rods only', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Methyl alcohol is oxidized by alcohol dehydrogenase into formic acid and formaldehyde. Formic acid by inhibiting cytochrome oxidase is toxic to neurons especially retinal ganglion cells. In methanol poisoning vision loss begins 12 hours or more after ingestion and progress to complete blindness with unreactive pupils and optic disc hyperemia.', 'role': 'assistant'}]