Why Do Cats Have 2 Eyelids?

By Phil / July 27, 2017
Why Do Cats Have 2 Eyelids

Have you stroked your cat’s head while it’s sleeping and noticed how it has an extra eyelid if their outer eyelid moves?

It’s sometimes called the inner eyelid, second eyelid, third eyelid, palpebra tertia for the scientific name, or extra eyelid. Whatever you want to call it, have you ever wondered why do cats have 2 eyelids?

This might come as a surprise, but it’s actually us that have the odd eyelid structure. Most animals have an extra eyelid, and it serves an important purpose for them.

Why Do Cats Have an Extra Eyelid?

The third eyelid is there to act as an extra layer of protection. Remember, cats can’t exactly reach up and wipe something out of their eye if it’s bothering them like we can.

The third eyelid not only stops a lot of debris and bits of dirt that will be uncomfortable, it helps to wipe the eye clean when they blink.

It also helps to keep their eyes moist, as well as keeping excess moisture out of their eyes, and protects them from too much sunlight.

Why Can I See My Cats Third Eyelid?

You shouldn’t see their third eyelid when cats are awake unless they are sick. Although, you may be able to see a tiny bit at the corner of their eye sometimes.

If you can see their extra eyelid while they are awake it may mean there is an underlying medical issue. Haw’s Syndrome is one such condition as I will explain below.

I would advise you take your kitty to the vet and have them check them over just incase there is a medical reason why their eyelid is not fully retracting when they are awake.

Eye issues are potentially very serious. It’s not like a wound or surface injury that will heal completely on its own.

If something is aggravating their eye it’s unlikely to clear up on its own, and it’s certainly not worth risking permanent damage to their vision.

What Is Haw’s Syndrome?

Haw’s Syndrome is probably the most common eye disease in cats. The main symptom is their third eyelids becoming visible, usually from the bottom of their eyes.

The condition is typically caused because there is another health issue, such as cat flu or parasites infesting the cat.

Once the underlying issue is resolved Haw’s Syndrome usually clears up at the same time. Your vet will be able to help your kitty, please take them as soon as you notice their eyelids showing.