Cats' Eyes

The ancestors of domestic cats, and other wild cats of similar size, primarily prey on small rodents, and these animals tend to be most active at dusk and during the night. The eyes of the cat are adapted to perceive objects in dim light, which is an obvious advantage in hunting. Cats have large eyes and the pupils are able to dilate widely in poor light. This allows as much light as possible to enter and fall onto the sensitive layer, called the retina, at the back of the eye. The retina of mammals contains special receptor cells, called rods and cones. Rod cells are sensitive to light of low intensity because of the presence of a pigment called rhodopsin (visual purple). The pigment alters when stimulated by low intensity light rays, and this causes nerve impulses to be generated, which are sent along the optic nerves to the brain where they are interpreted. Cone cells are stimulated by bright light and produce sharper images than rod cells. They are responsible for the detection of color, containing pigments that alter at different wavelengths.

Cats' eyes contain a high proportion of rod cells compared to cones, a ratio of 25 rods to each cone. Experiments have shown that the cone cells of the cat are sensitive only to blue and green and there is no perception of red. Cats, in common with many other mammals, have a layer called the tapetum lucidum behind the retina, which is stimulated for a second time producing an intensified image. The tapetum lucidum can be clearly seen if a light is shone into the eyes of a cat at night when they appear to glow a greenish-yellow color-'cats' eyes'. Compared to human beings, cats have poorer daytime and color vision. They are able to detect moving objects better than static ones. In poor light, however, the visual acuity of the cat greatly exceeds that of a person and, combined with its other keen senses, helps to make it a superbly efficient twilight hunter.

Cats Care
Acquiring A Cat
Cat Diet
Cat Grooming
Adaptations of Cat
Cat's Behaviour
Cat's Language
Cat Breeding
Elderly Cat Care
Cat Parasites
Cat Illnesses
First Aid for Cats
Cat Training