This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Optics and Errors of Refraction, Subject name: Ophthalmology
[{'content': 'Visual acuity of eye is: \nSelect and explain. \nA. Refractive power of eye, B. Ability to discriminate two points, C. Ability to increase converging power of eye, D. limitaion of occular movements', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Measurement of the threshold of discrimination of two spatially separated targets (a function of the fovea centralis) is termed visual acuity. Refractive power of eye-= +60D(+45D by cornea +15 D by lens). Ability to increase converging power of eye ACCOMODATION limitaion of occular movements - Diplopia', 'role': 'assistant'}]