Ophthalmology In retinoscopy for refractive error at lm we add -1 D. If done at a distance of 66 cm, the addition factor will be: A -2D B -1.5 D C -0.5 D D -5 D 💡 Explanation In retinoscopy for refractive error at lm we add -1 D. If done at a distance of 66 cm, the addition factor will be: ✓ Correct Answer: B. -1.5 D