This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Optics and refraction, Subject name: Ophthalmology
[{'content': 'During retinoscopy of a 30 year old male, which cycloplegic is used routinely- \nSelect and explain. \nA. Atropine 1% ointment, B. Cyclopentolate 1% drop, C. Homatropine 2% drop, D. Atropine 10% drop', 'role': 'user'}, {'content': "Answer: B \nExplanation: Cyclopentolate is a sho acting cycloplegic. Its effect lasts for 6 to 18 hours. It is used as 1 percent eyedrops in patients between 8 and 20 years of age. One drop of cyclopentolate is instilled after every 10-15 minutes for 3 times (Havener's recommended dose) and the retinoscopy is performed 1 to 1/ 1/2 hours or 60 to 90 min. later, after estimating the residual accommodation which should not exceed one dioptre. Reference : A K KHURANA OPHTALMOLOGY,Edition 4,Page-550", 'role': 'assistant'}]