Your Cat’s Eyes and Vision: The Complete Guide

Wondering about your cat's eyes and vision? We've researched the topic to bring you answers to some of the most common questions cat lovers have about how their kitties see the world.

 

It seems that cats can see everything we do and in some instances, much more than we are capable of seeing! The mechanisms in a cat's eye are precision-designed for detecting motion, which comes in handy when they are hunting small prey that may not be easily detectable in thick undergrowth or tall grass.

When hunting, a cat first relies on its extremely sensitive hearing and directional ear movement to locate the general location of prey, then targets and captures the prey using its very sharp eyesight. Cat vision is fine-tuned to capture even the slightest movement which is often imperceptible to humans. This makes the cat one of the most successful hunters on land.

How Do Cats See?

We know that cats most likely possess binocular vision, (overlap in the images from each eye) and are capable of seeing in three dimensions, as do humans. Their visual field of view is estimated to be around 200°, versus 180° in humans, with a binocular field much narrower than that of humans.

As with most predators, a cat’s eyes face forward, affording a larger degree of depth perception at the expense of the field of view. Field of view is largely dependent upon the placement of the eyes, but may also be related to the eye's construction. Many of us have watched in awe as our cats have exercised the ability to jump from as much as 6 feet onto a narrow window ledge without touching the window. This truly amazing feat would require not only excellent balance but also precise distance judgment, which is offered by the unique mechanics of their eyes.

Can Cats Really See In The Dark?

Cats appear to be slightly nearsighted, which would suggest that their vision is better suited for picking up minute detail in closer objects, such as prey. Objects farther than several hundred yards away don’t normally catch the interest of a cat due to their lack of ability to focus on it clearly. Cats have both rods and cones in the retina. Rods are the receptors that the eye uses for precise nighttime sight and picking up the most minute detail in a sudden movement. Cones are used during the daytime to distinguish color. Cats have more rods than cones, as compared to humans, making cat night and motion vision superior to humans.

Cats have an elliptical pupil that opens and closes much faster than round types. This allows for a much larger pupil size into which more light can pass. Cats also have a mirror-like membrane on the back of their eyes called a Tapetum. This membrane’s job is to reflect the light passing through the rods and then send it back through the rods a second time in the opposite direction. The result is a double exposure of the light, which permits cats to see extremely well in near darkness.

In low light or at night, cats do not see color differences. They see only black, white and shades of gray.

Can cats see in total darkness?

Although a cat cannot see in total darkness, a partly cloudy night sky with some stars will provide enough light for cats to hunt and see movement, even in the cover of most brush. The yellowish glow you see when shining a light in a cat's eyes is really that light reflecting off the Tapetum membrane.

While cats can't see anything in total darkness using their eyes, they can still get a good idea of what's going on around them. They use their keen senses of smell and hearing to get more information about their environment. They can also get sensory information from their whiskers. The long whisker hairs - also known as vibrissae - can pick up slight changes in the air which let the cat know prey is moving nearby.

Do Cats See In Color?

The answer is yes, they do. But they probably don't see as many colors as we do, or as vividly. Having so many rods makes them our superiors in night vision, but not where it comes to day vision.

What colors do cats see best?

In cats, blue and green appear to be the strongest colors perceived and they also seem to respond to the colors within the purple, green and yellow range. Red, orange and brown colors appear to fall outside cats' color range and are most likely seen as shades of gray or purple. Nobody knows for sure though because color is a perception as much as it is actual signals coming into the eye.

Cat's pupil size and its meaning

If you share your life with a cat, you probably noticed by now that their pupils can change in size. The feline pupil can be anything from a narrow slit to a full-fledged huge saucer that fills up almost the entire surface of the eye.

What could this mean? There are two possible reasons for a this change occurring in a cat's eyes.

A reaction to the amount of light in the environment

In low-light conditions, the pupil will become larger, allowing more light to get through and hit the lens and eventually, the optic nerve. As more light enters the eye, the cat can see more detail in the environment around her. However, in a well-lit room, Kitty's pupils will constrict, to protect the eye from being overwhelmed by too much light.

If you've ever had your eyes tested by an ophthalmologist, they probably used special drops to make your pupils wider. When under the effect of the drops, you may have noticed the world looks "too bright". That's the effect that a constricted pupil prevents. And yes, human pupils can change their size too in reaction to light. Albeit, the effect is usually less impressive than it is in the cat.

An emotional reaction (usually fear)

When a cat feels threatened, he or she will experience a "fight or flight response". Their entire body becomes focused on the perceived danger. As they try to absorb every last bit detail of the environment, the pupils usually widen as part of this response.

That doesn't mean that a cat with constricted pupils is necessarily relaxed. If there's a lot of light around, the pupils may remain at least partially undilated. If you suspect that your cat is in a state of fear, be careful. Kitty may lash out at you if you try to pick her up or even pet her. Read more here about redirected aggression in cats.

What Is "The Third Eyelid?"

Cats are unique in that they have a third eyelid, the nictitating membrane, which is a thin cover that closes from the side and appears when the cat's eyelid opens. The nictitating membrane has many functions; temperature adjustment, clearing the eye of foreign matter and particles, and sweeping moisture over the entire eye.

This membrane partially closes if the cat is sick; although in a sleepy, content cat this membrane is often visible. If a cat chronically shows the third eyelid, it should be taken to a veterinarian for evaluation.

Cat eyes in various breeds

It's worth noting that some breeds have typical eye colorations, as well as unique eye shapes. The official breed description will always specify the allowed eye colors and shapes for that breed. For example, the CFA's breed standard for Persian cats mentions eye color by the cat's coat color. For white persians, for example, it says -

Eye color: deep blue or brilliant copper. Odd-eyed whites shall have one blue and one copper eye with equal color depth.

For Bengal cats, the CFA breed standard describes both the shape and color of the eyes in the same section -

EYES: Shape is round to oval. Large, but not bugged. Set wide apart, with a slight bias toward the base of ear, when oval in shape. Eye color independent of coat color, except in the Lynx Points, where Blue is the only acceptable color. Richness and depth of color is always preferred.

Ethical breeders work hard on preserving certain looks in the breed, and eye color certainly comes into play when planning a breeding program.

Types of Eye Color In Cats

Cats have a wide variation in eye color, the most typical colors being golden, green and orange. Blue eyes are usually associated with the Siamese breed, but they are also found in white cats. If a white cat has two blue eyes, it is oftentimes deaf; however, orange eyes usually indicate the cat is free of hearing problems.

White cats having one blue and one other-colored eye are called "odd-eyed" and may be deaf on the same side as the blue eye. This is the result of the yellow iris pigmentation rising to the surface of only one eye, as blue eyes are normal at birth before the adult pigmentation has had a chance to express itself in the eye(s).

Eye color in kittens

Kittens are born blind, with their eyes shut. The usually begin to gradually open their eyes at around two weeks of age. At that point, the eye color is usually blue or bluish gray.

Most kittens grow out of their blue eyes. This is a gradual process, as eye color gradually metamorphoses from blue to bluish-green, then to green and finally to yellow. If the cat is genetically predisposed to having blue or green eyes, the color will stay that way into adulthood, but otherwise, it will gradually change.

The reason for the change in the kittens' eye color is the lack of pigments in the iris. The eye color pigment, melanin, is produced by special cells in the eye, called melanocytes. Melanin is produced by these cells over days and weeks after birth, in response to light. As long as the kittens' eyes are shut, no melanin is produced and that's why the eyes are blue at first.

 Let's take a look at some interesting eye colors in cats.

Cats with Yellow or Golden Eyes

Yellow is possibly the most common color for cat eyes. It can be found in the general pet cat popularion, as well as in many cat breeds.

Cats with Green Eyes

Green is often a variation of yellow eyes, with the greenish hues appearing in part of the iris. In some breeds, breeders work to achieve a stronger and more vivid green color.

Cats with Blue Eyes

Blue eyes are typically seen in colorpoint cats or white cats. They are a breed requirement in the colorpointed breeds such as the Siamese and Himalayan cats.

Blue eyes can be seen with other color variations, such as this Calico, but this is a rare occurrence.

Cats with Orange or Copper Eyes

One of the most beautiful and unique cat colors, the copper or orange eye color can be seen in many breeds, as well as in pet house cats.

Final Words

Having such a strong sense of vision, cats are truly one of nature’s greatest creatures, capable of seeing much more than our own human eyes are able to process. Their keen vision not only allows them to hunt prey with precision, but it also enables them to escape being some other animal's prey. Of course, being able to see a treat as it approaches is a wonderful advantage to them in terms of their survival.

Next time you gaze lovingly into the soul of your beloved cat through those limpid pools of color, you will know not only that they freely and generously return your loving affection but that they can also see deeply into your own soul as well.

Part of this article was written by Gaye Flagg

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