The Exceptionally Unique Eyes of Cats

Tabby cat's face with yellow eyes closeup

Looking into your cat's eyes may teach you a lot, just like it does with people. Normal cat eyes should have equal-sized pupils. Any variety of disorders, from minor to serious, can be indicated by a change in the pupil size of one eye. These consist of:

  • Inflammation of the eye
  • Horner's syndrome (a )
  • FeLV (may cause pupillary spasms)
  • Tumors
  • Central nervous system injury

The "Third Eyelid"

The nictitating membrane, or inner third eyelid, of cats shields the eye from injury and/or dryness. The third eyelid will partially cover over a cat's eyes when it is ailing. This is a warning to take him to the veterinarian right away. Strangely enough, a cat that is really joyful will likewise display that nictating membrane.

Moody Eyes

The author of "What Makes Cats Work" claims that "his moods are reflected by his eyes, like many other physical traits of the cat." "The telltale sign of an angry cat is a shift in pupil size, whereas an enthusiastic or scared cat would have wide-open eyes and huge pupils. The eyes of a relaxed, content cat will occasionally look a little darker than usual. This one is merely an observation; I have no explanation."

Diseases and Conditions of the Eye

Cats can get a variety of the same ailments that occasionally affect humans, including as cataracts, glaucoma, and conjunctivitis (pinkeye). The latter may spread to people if it is brought on by the chlamydia bacterium.

It is critical that you take your cat to the doctor at the first indication of trouble since cats' eyes are so fundamental to their general wellbeing. Many diseases are easily treatable if discovered in time, but if left untreated, they can result in months of veterinarian expenses and even blindness.

Cats' Night Vision

Human night vision is far inferior than that of cats. They cannot see in complete darkness, but they can see with only one-sixth of the light we require to see. In cats, the muscles that surround the pupils in the iris may contract to a vertical slit in strong light and fully open in extremely low light to provide maximal lighting.

Additionally, the tapetum lucidum, a reflective layer located below the cat's retina, reflects incoming light and bounces it off the cones to maximize the usage of already-present light. The bright green orbs that appear when a cat's eyes are lit up at night are most likely caused by the tapetum.

These special feline features have probably developed for survival purposes, as wild cats are nocturnal and do much of their hunting at night.

Testing Cats' Eyes to Help Humans

A group of researchers from the University of California, Berkeley, employed cats to study human eyesight in 2000. The researchers, lead by Yang Dan, associate professor of molecular and cell biology, sedated the cats before implanting electrodes in their brains and showing them photos as part of the contentious experiment. The cats' reactions to light and dark could be recorded, and using a mathematical equation, the signals could be transformed into pictures.

Since cats' eyes are so similar to humans, the team hoped to answer a number of questions about how the eye and the brain work together to capture, encode, and reassemble images.

Cats Eye Trivia

  • Cats cannot see directly beneath their noses. You can test this by offering your kitty a treat. He can smell it, but if you drop it directly beneath his nose, he'll have to root around a bit before finding it.
  • Rumors aside, . Their ability to see color is not as enhanced as ours, but they can see some colors.
  • If normal human vision is 20/20, then that of the cat is 20/100. It has keen vision for objects far away, but things up close may appear fuzzy or blurred. Perhaps this is why cats do the sniff test when greeting friends.
  • Most white, blue-eyed cats are . A white cat with odd eyes (one blue and one green or gold) will most often be deaf on the side with the blue eye.
  • Cats "kiss" with their eyes. Of course, a nip on the nose is also their way of giving a kiss. If you want to show your cat you love him, give it a kitty kiss right back. Not on the nose. Just give it that long stare and slow blink and see what happens.
If you suspect your pet is sick, call your vet immediately. For health-related questions, always consult your veterinarian, as they have examined your pet, know the pet's health history, and can make the best recommendations for your pet.