Why Do We Have Two Eyes?

Having two eyes gives humans binocular vision — each eye sees the world from a slightly different angle (about 6 cm apart), and the brain combines these two images to calculate depth through a process called stereopsis. This is critical for judging distances accurately, essential for tasks from catching a ball to driving. Two eyes also provide a wider field of view (about 200° combined versus about 150° for one eye) and serve as biological redundancy: if one eye is damaged, the other can still function. Predators tend to have forward-facing eyes for depth perception, while prey animals often have side-facing eyes for a wider field of view.