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: Social & Preventive Medicine
[{'content': 'Ethambutol is associated with \nSelect and explain. \nA. Red-green colour blindness, B. Red-blue colour blindness, C. Blue-green colour blindness, D. Yellow-green colour blindness', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ethambutol may cause ‘optic neuritis’ (ocular toxicity): 463 National Health Programmes, Policies and Legislations in IndiaReview of Preventive and Social Medicine\nIt may lead to ‘red-green color blindness’\nPatients may thus develop ‘blue vision’\nThus it is contraindicated in children < 6 years age, as they may not be able to report any deterioration of color vision.', 'role': 'assistant'}]