The presence of the tapetum can be observed at night when a pair of glowing eyes reflects back a flashlight or some other light source. (Interestingly, different animals have different color ...

“If you ask people what animal eyes are used for ... presumably because color vision is less important at night and because cones are most effective in bright daylight. Most mammals are still ...

Nocturnal geckos have superb vision in dim light - their eyes are 350 times more sensitive to colour at night than a human's (see for yourself with our animal vision interactive). Lacking eyelids, ...