Why do cats have three eyelids in each eye?

Answer 1

Who knows, just they way it is supposed to be. Why do we only have one? My cats will sometimes sleep with their outer lids open, so they look really creapy.

Answer 2

Most animals do have a third eyelid. It is basically just an extra fold of conjunctiva supported by a little 'T' shaped bit of cartilage.

It provides extra physical protection for the eye (e.g. in diving mammals, which normally have a clear membrane, or in birds of prey, where it functions to remove grit/debris from the eyes). It also contains a gland that contributes to the tear film (needed to keep the eyes moist so as not to damage the cornea).

In cats, it's also a non-specific indicator of illness- if the upper and lower lids are open, the third eyelid should be open also. If the third eyelid is drawn partially across the eye with the eyelids are open, it frequently means that the cat is unwell. Spasm of the third eyelid is also a diagnostic sign of tetanus in all species.

Answer 3

I would think this would relate to when they are locked onto a pray and hyperfocus. The third eye lid would clean their eyes without them loseing their target.

Also the older breeds, "Big Cats" (another words lions, tigers,.. etc), and back in time had to deal with constant environmental things bothering their eyes... I don't know how else to explain it, but when your in an area with alot of pollen or water there is always something getting into your eyes. Tigers end up in water, Lions end with with dust and animals they are chaseing kicking things around and the debris and dust landing in their eyes,.. some cats live in areas where there is constantly snow... every where so that gets into their eyes. Do you catch on to what I mean by Environmental?

The Third eye lid is more common with animals that end up submergeing in water, going through dark places (night vision), and some environmental situations (creatures that end up trying to hold still in a very dry or very wet environment).

Hopefully someone else will know ALOT on this and get very technical. I don't like the people that just pull up random sites and say that's the answer because some websites do not produce true or acurate information,.. so I'd like to see what someone actually types out.

Answer 4

I don't know the real answer either. Certainly it can protect the eye and can be a sign a cat is not well when it is drawn partially over the eye.

Many animals have this protection from environmental assault to their eyes. Since our housecat descended from a small desert cat animal it certainly was for them a protection in sand storms. The camel has this feature too.

Answer 5

Yes, he is sick with something. Usually, gastro-intesinal issues (especially worms) can cause a cat's 3rd eyelid to appear. Take him to the vet to get a proper diagnosis. My neighbor's cat once had his 3rd eyelid showing. Several days passed and the cat's eyes were still the same. It bothered me so much that I asked my neighbor to take her cat to the vet. Said she didn't have the money. So, I myself took her ct to my vet. Turned out the cat had tapeworms. It was easily treated.

Answer 6

The third eyelid is called a nictating membrane. It rises automatically and then moves sideways across the eye to protect or lubricate its sensitive surface.

Blah, blah, blah I know everything. Excuse me for trying to help. I looked it up somewhere else and it said both of our answers. Get over yourself.

Answer 7

wasn't aware that they had 3 eyelids, interesting point.

Answer 8

Cats in nature are nocturnal animals and it helps them when they hunt.

Answer 9

They can't have four eyelids.

Answer 10

Its just the way nature intended!!!