In mammals, teeth vary in size, shape, number, and function. Depending on what the animal eats, it may have teeth specialized for cutting, tearing, grinding, shearing, or gnawing. The teeth of the porpoise, seal, deer, cat, rabbit, and anteater illustrate some of these different kinds of teeth. We can't tell how good an animal's eyesight is just by looking at the animal, but we can get some information by looking at the placement of the eyes. For example, a one-eyed person has difficulty in judging distances.
Depth perception is important in animals, such as hawks and owls, in order to hunt on the wing.
Depth perception comes from the amount of overlap in the field of vision of the two eyes. Therefore, the greater your depth perception, the smaller the area you can see. A bird with its eyes placed to the side can see a much greater area without turning its head than an owl, whose eyes are close together, can, but it does not have depth perception. Think about what other types of lifestyle require depth perception. Depth perception has evolved in many different groups of animals and is not necessarily associated with a predatory life style.