Relative afferent pupillary defect is characteristically seen In damage to -
For testing relative afferent pupillary defect (RAPD), a strong, steady light is used. The light is shined into one eye, and then quickly switched to the other. This is repeated back and foh, until one of four conclusions is reached (listed below). Since light in one pupil causes both pupils to constrict, quickly switching from one eye to the other will give a "relative" indication of the functioning of each eye and optic nerve. If both eyes are equally dysfunctional, no "relative" defect would be found.
Optic nerve
Optic tract
Lateral geniculate body
Occulomotor nerve
Neuro-ophthalmology