Primates evolved binocular vision (both eyes facing forward) so that they can see in three dimensions, critical as they jumped from branch to branch. Higher primates developed color vision to better hunt out ripe fruit. Optical illusions succeed because they exploit the limitations of our visual processing. Wrong! All of these beliefs are false. The author's research centers on the "why" of human vision : why we have binocular vision, why we see in color the way we do, why optical illusions work. He also looks at why are we able to absorb information by readinga very new invention from an evolutionary perspectivemore readily than by hearing, which we've evolved to do over hundreds of thousands of years.