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': 'Keratometry used for? \nSelect and explain. \nA. Measuring curvature of anterior surface of cornea, B. Calculating Axial length of eyeball, C. Endothelial cell count, D. Intraocular pressure', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Measuring curvature of anterior surface of cornea Ketatometry -o A keratometer, also known as a ophthalmometer, is a diagnostic instrument for measuring the curvature of the anterior surface of cornea. Keratometer reading provide the following information to assist in the overall assessment of the corneai) Radii of curvature of the corneaii) The degree of corneal astigmatismiii) The direction of the principal meridians of the eye, determining whether the astigmatism is with the rule or against the rule a key factor in contact lens fitting.iv) The presence of any corneal distortion.", 'role': 'assistant'}]