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': 'Methods to measure error of refraction are all except- \nSelect and explain. \nA. Retinoscopy, B. Refractometry, C. Keratometry, D. Binocular balancing', 'role': 'user'}, {'content': "Answer: D \nExplanation: The final step in the subjective refraction is binocular balancing--a process sometimes known as 'equalizing the accommodative effo' or 'equalization of vision'. This allows both eyes to have the retinal image simultaneously in focus. Reference : A K KHURANA OPHTALMOLOGY, Edition4 ,Page-557", 'role': 'assistant'}]