Which of the following represent the average distance of the fovea from the temporal margin of the optic disc?

Fovea centralis is the central depressed pa of the macula. It is situated about 2 disc diameters (3mm) away from the temporal margin of the disc. It is about 1.5mm in diameter and is the most sensitive pa of the retina. It is tightly packed with cones and there are no rods. Ref: Comprehensive Ophthalmology By A K Khurana, 4th Edition, Pages 249, 251.