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': 'The earliest change in glaucoma is: \nSelect and explain. \nA. Papilloedema, B. Hazy cornea, C. Baring of the blind spot, D. Sickle scotoma', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. Baring of the blind spot', 'role': 'assistant'}]