The Complete Cat: Cat Eyes

The eyes of a cat are designed to give him the greatest chances of seeing his prey before it sees him. Cats are nocturnal in nature, and nightime is hunting time for the big cats, as well as their domestic brethren. The feline vision is remarkable in that cats can see clearly in just 1/6th the light that humans need to see, likely a result of the reflection of the tapetum lucidum, located below the retina. It is this tapetum lucidum which causes cats' eyes to shine in the darkness, and to cause flash photos to display neon green in the eye area.

Cats' field of vision is designed to find prey in a relatively wide area (120 degrees in front, and 80 degrees to each side). Combined with their keen sense of hearing and smell, this provides a distinct advantage for the feline predator.

Kittens are all born with blue eyes. Their eyes gradually change to their permanent color in the first few weeks of life. Eye color is related to several genetic traits. For instance: most blue-eyed white cats are deaf. Although it was once commonly felt that cats were colorblind, we now know that they can distinguish red and green. Perhaps there will be "seeing-eye cats" in the future.

Like many other physical characteristics of the cat, his moods are reflected by his eyes. Pupil size changes are the clue: an angry cat will have narrowed pupils, while an excited or frightened cat will have eyes wide open, with large pupils. A mellow, happy cat's eyes will sometimes appear a shade darker than normal. I can't explain this one; it's just an observation.

Cats also use their eyes aggressively, to make direct contact with the eyes of a potential rival. The other cat may look away in submission, or a territorial battle may ensue.

It is believed by some feline behaviorists that cats use a slow eye-blink to demonstrate love, an expression which can be mimicked in return by its human companion.