How Does a Cat's Eye Work, Understanding Feline Vision

Cats by nature are nocturnal. If you have a cat then you know that your cat probably likes to wander the house at night in the pitch dark. You may have found yourself aggravated at your cats endless chasing of things you can't see. If you have ever wondered how a cat's eye works you may be surprised to find out that it is actually quite different from yours. To better understand feline vision you must understand it as an evolutionary change that has helped your cat find prey without finding itself as prey. Lets cover the hows and why of a cat's eye by breaking the eye down by its functional components.

Pupil
Due to your cat's eye needing to work in the dark the pupil of your cat can expand much larger than a human eye. The expansion of the pupil allows more light to enter the eye. Enlarged pupils come at a cost. Anyone who has ever had their eyes dilated has no doubt noticed a lack of depth perception when you leave the doctors office. The additional light prevents detailed vision at a distance, thus the reason you nor your cat should be allowed to drive when your pupils are maxed out. The enlarged pupil of a cat allows your cat's eye to make maximum use of the smallest amount of light available to the eye. If you have ever wondered why your cat's eye has an elongated pupil it may help to know that this enables the pupil's expansion.

Lens
Just like a human eye, light passes through the pupil and is collected by the eye lens. A cat's eye has a much larger eye lens than a human eye once again allowing your cat's eye to make maximum use of a small amount of light. If your cat has ever appeared clumsy or if you think they knock things over that are right next to them it is not because of poor feline vision. The large lens of the cat's eye makes it difficult to see things close up. This is unlike the human eye where the lens can change shape to see things over different lengths. The large lens benefits the cat by allowing them to see things far off, thus the reason your cat may seem like he or she is staring off into the distance.

Retina
A cat has very large eyes, and thus has very large retinas. The retina of the eye works to recognize light and responds to light according to the size and shape of the lens. The large retina found in a cat's eye acts as a large TV antenna for the optic nerve. The larger the retina the better the image appears. It is the difference in a small television and a large television, the larger television is easier to see due to the people on the screen being larger. Larger retinas allow a cat's eye to see things in a larger perspective than a human eye.

Color
The fact that a cat's eye has larger pupils, thicker lenses, and larger retinas all add up to one huge disadvantage for a cat when compared to a human eye. A cat has a very hard time seeing color and detail, whereas the human eye is made to efficiently make use of the color and details that surround them. Evolution over time has made the feline vision react in a way that benefits the nocturnal nature of the cat and this helps serve the cat's ability to hunt and find food which to a cat is more important than watching a color television.

The etymology of a cat's eye is very interesting and makes sense when understanding your cat as a predator instead of a couch potato. Your cat was made to hunt and its eyes are well suited for it.