system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
In retinoscopy for refractive error at 1m, we add 1D ; if done at a distance of 66 cm, the additional factor will be –
assistant
The correct answer is  Deduction of 1D for lm and 1.5D when retinoscopy is performed at 2/3rd m (67 cm) distance.