This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cornea, Subject name: Ophthalmology
[{'content': 'Fluoresciene stain is used in the eye to stain - \nSelect and explain. \nA. Cornea, B. Retina, C. Choroid, D. Iris', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Cornea Important corneal examinationsUsed foro Keratometry, Corneal topography o Specular microscopyo Slit lampo Padiymetero Placido's disco Fluorescein. Alacian blue & Ben sal rose staino Window reflex, slit lamp biomicroscopy, Placidos' discCurvature of cornea Corneal endothelial densityCorneal opacity Thic kness of cornea Corneal sheen Corneal stainingCorneal surface", 'role': 'assistant'}]