All vertebrates have two eyes. They are thus able to observe a wider panorama than would be the case if they had only one. Binocular vision also offers a second advantage, namely depth perception. This “stereoscopic vision” arises from the fact that the two eyes observe the world from slightly different positions. Panoramic vision and stereoscopic vision involve conflicting requirements. For the widest panorama, the visual fields of the two eyes must meet, but without overlapping. Depth perception in as large as possible an area of the visual field, by contrast, requires that the visual fields overlap as far as possible. Some animals have opted for panoramic binocular vision and thus for laterally positioned eyes. These are mainly the herbivores, which need to escape as soon as they scent danger in their surroundings. Other species have abandoned panoramic vision in favor of depth perception in as large a binocular field of vision as possible; their eyes have adopted a frontal position. This group consists mainly of predatory animals, which must be able to accurately estimate the distance to their prey, and tree-dwelling species, which need to know how far it is to the next branch if they are to jump successfully. Among the animal species, the apes have the most highly developed visual co-ordination of front leg movements.