The comparatively large area of the primate brain devoted to vision is partly explained by the fact that primates must process a larger amount of visual "input" to the brain than many other ...

Heesy, C. P. Ecomorphology of orbit orientation and the adaptive significance of binocular vision in primates and other mammals. Brain, Behavior and Evolution 71, 54-67 (2008). Huxley, J.

Tarsiers' eyes are large but they don't move - meaning the primates must swivel their heads to scan their environment ... The reptile can also switch between monocular vision - when both eyes are used ...

That’s a poor substitute for color binocular vision for a primate, but for other animals, at other times, that kind of information has been crucial to survival, says ophthalmologist Ivan R.