is vision in which both eyes are used together. Having two eyes confers at least four advantages over having one. First, it gives a creature a spare eye in case one is damaged. Second, it gives a wider field of view. Third, it gives binocular summation in which the ability to detect faint objects is enhanced. Fourth it can give stereopsis in which parallax provided by the two eyes' different positions on the head give precise depth perception. Such binocular vision is usually accompanied by singleness of vision or binocular fusion, in which a single image is seen despite each eye's having its own image of any object. Other phenomena of binocular vision include utrocular discrimination, eye dominance, allelotropia, and binocular rivalry.
Classified under Perception Definition contributed by RPoldrack about two months ago.