This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diseases of Cornea, Subject name: Ophthalmology
[{'content': 'Corneal sensations are diminished in: \nSelect and explain. \nA. Herpes simplex, B. Conjunctivitis, C. Fungal infections, D. Marginal keratitis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Herpes simplex infection is a common cause of corneal sensory loss, although less severe than in keratitis caused by reactivation of varicella-zoster virus. Some patients with active HSV keratitis present with sensations of spontaneous pain, discomfo, and dryness.', 'role': 'assistant'}]