This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Retina, Subject name: Ophthalmology
Distant direct ophthalmoscopy is done at 
Select and explain. 
A. 100 cm, B. 25 cm, C. As close to the face as possible, D. 1 m
B: 25 cm
Answer: B: 25 cm 
Explanation: Ans. (b) 25 cmDistant direct ophthalmoscopy is done from a distance of 20 - 25 cm, and the features of the red reflex are noted.Option a/d are the same (mathematical conversion), so rule them out distance for retionscopy.Option c - distance for Direct ophthalmoscopy.