Eyes and Vision

An eye is an organ of vision that detects light. Different kinds of light-sensitive organs are found in a variety of organisms. The simplest eyes do nothing but detect whether the surroundings are light or dark, while more complex eyes can distinguish shapes and colors. Many animals, including some mammals, birds, reptiles and fish, have two eyes whose fields of vision largely overlap, to allow better depth perception, as in humans; and others are placed so as to minimize the overlap, such as in rabbits and chameleons.