nubbsgalore:

the red eyeshine of the alligator occurs when light enters its eyes, passes through the rods (light receptors) and cones (color receptors) of the retina, strikes a membrane behind the retina called a tapeatum, and is then reflected back through the eye to the light source. most of the animals with eyeshine are, like alligators, night hunters who must make use of limited light. (photos xx)