Relative Afferent Pupillary Defect (RAPD) is a condition in which pupils respond differently to light stimuli shone in one eye at a time due to unilateral or asymmetrical disease of the retina or optic nerve (only optic nerve disease occurs in front of the lateral geniculate body).
Eye doctors use three tests to assess pupil reflexes: the light response test, the swinging flashlight test, and the near response test.
The entrance pupil is the apparent aperture as seen from the object side.
The entrance pupil is the image of the lens’ aperture stop as seen from the front of the lens — through the glass elements in front of the iris — and that is normally where the iris is located.
Direct reflection—also known as specular reflection—is the mirror-like reflection of a light from a surface in which the light from a single incoming direction is reflected in a single outgoing direction.
The consensual reflectionis any reflection observed on one side of the body when the other side has been stimulated. This reflex is evidenced mainly in the process of contraction of the pupil of both eyes by illuminating only one of them (Dictionary, 2017).