A cat’s eye is not only different from a human’s eye, but it is also different from most other primates, too. Other than humans and these primates, most animals have a third eyelid that sweeps across the cornea when it blinks, acting as a windshield wiper, so-to-speak. It clears dirt and debris and creates about 50% of the animal’s tears. This third eyelid that is a retractable membrane, is known as the nictitating membrane and it is located on the inner corner of each of a cats’ eye. This is the corner that is the closest to the cat’s nose.
What is this third eyelid?
First of all, you should not be seeing this third eyelid, so if you are ever able to see this lid, this means that there is some sort of problem and yo need to have your cat examined by her veterinarian as soon as possible. There are multiple reasons that can cause this third eyelid to stick out and be visible. There is an eye condition known as pink eye, or, conjunctivitis, that can cause this problem. This is an inflammation of the eye membranes. Other issues include, glaucoma, uveitis (intraocular inflammation), a mass growing on the eyelid (a neurological disorder of the eye known as Horner’s syndrome), ulcers on the cornea, plus others.
According to Dr. Nancy Bromberg VMD, MS, Dipl. ACVO, a board-certified ophthalmologist at VCA SouthPaws, located in Fairfax, VA, “The gland of the third eyelid sometimes gets inflamed and swollen and everts the third eyelid. This is commonly known as ‘cherry eye.’ It interferes with normal function of the third eyelid and should be surgically repositioned. This condition is most common in the Burmese [cat breed].”
If you see your cat’s third eyelid, here’s what you need to do
You should seek the help of a veterinarian for an exam of your cat if you should ever happen to see either one, or more of your feline’s third eyelids. If you should happen to see just one of your cat’s third eyelids, this might indicate that it is only that particular eye that is having a problem, however, if both of your cat’s third eyelids are showing, your cat might be dealing with an illness, especially if he is acting ill. It may not even be related to the eyes, so don’t delay seeing a vet for help.
It’s important to get your cat to the doctor as soon as you can, because having the third eyelid visible means that more than likely, your cat is in pain or having discomfort, at the very least. Your veterinarian will want to do a full exam of your cat’s eyes and check for things like corneal ulcers, and check the intraocular pressure in her eyes. Once your vet has done the exam and knows what the problem is, they will be able to get your cat on the right treatment program to help alleviate the discomfort, and get your cat back to better health.