Cats have superior night and peripheral vision since they are crepuscular or active during dusk and dawn and they have a 200-degree field of view compared to a human’s 180 degrees view. Thus, it can be alarming if you notice your cat squinting and keeping one eye closed as it hinders your cat from being her usual active self.
Why is my cat keeping one eye closed?
Here are the most common reasons why your cat is keeping one eye closed:
1. It may be due to an eye infection.
Your cat may be keeping one eye closed because of a bacterial eye infection. The signs include redness around and in the eye, excessive production of tears, constant blinking and a protruding eyeball. Your vet may prescribe antibacterial eye drops for treatment. Do not attempt to use human eye drops as it may just aggravate her condition.
For viral or fungal eye infections, your vet may prescribe topical ointments or systemic antibiotics.
2. It may be due to eye irritation.
Eye irritation due to irritants in the environment may be the culprit. This may include cleaning chemicals, dust, tobacco smoke and strong perfumes and symptoms may include squinting, redness and discharge. What you can do is to rinse your cat’s eye with an eye-wash solution to provide relief. However, if you notice no improvement you should bring your cat to the vet.
3. Your cat may have conjunctivitis.
Feline conjunctivitis happens when there is an inflammation of the mucous membrane that lines the eyeball’s exterior and the inside of the eyelids. Similar to the pink eye in humans, it is contagious and may be passed from one cat to another. Its main cause is an upper respiratory illness due to a virus or bacterial infection, according to the Cornell University College of Veterinary Medicine.
The symptoms may include a discharge that has a yellow, gray, green or dark rusty red color. One or both eyes may be affected and you may also notice that your cat is sneezing or has nasal discharge. This condition may be treated with topical antibiotics like ointments or drops. However, if conjunctivitis was caused by the feline herpes virus, your vet may prescribe further treatments in addition to topical medication.
4. It may be due to glaucoma.
Another reason why your cat may be keeping one eye closed could be glaucoma which happens when an eye infection is left untreated. Other causes may include inflammation, anatomical abnormalities, trauma and tumors. Pressure builds up when fluid is not drained through the tear ducts and this may cause pain. As a result, your cat won’t be able to open the affected eye, become agitated and may yowl and hide.
The symptoms may include dilated pupils, thin and watery discharge, cloudy and discolored iris, clawing or pawing at the eye and visible swelling in the eye. Your vet may prescribe steroidal eye drops to reduce swelling and manage pain. At the earliest symptoms, bring your cat to the vet at once since if left untreated your cat may eventually lose her eye.
5. Your cat may have corneal ulcers.
Corneal ulcers may occur when corneal layers are depleted and it may be caused by trauma or infection. The symptoms may include a clear film over the eye, excessive discharge, cloudiness in the affected area, redness and sensitivity to light. Your vet may prescribe antibiotic eye drops but if the ulcer is deep down the eye, surgery may be required for its removal.
6. There may be a foreign object in your cat’s eye.
Your cat may have been extra playful and a foreign object got trapped inside her eye. This may be a small stone, dust and grit or ingrown fur or hair. Cats usually do not blink often which makes their eyes prone to irritations. Symptoms may include squinting, excessive tear production, pawing at the eye and rubbing her face on the floor. If your cat has a foreign object in her eye, remove it immediately by washing with warm water and saline solution. If the particle is still there, bring her to the vet at once.
7. It may be due to an inflamed eyelid.
Your cat may be keeping one eye closed because of blepharitis or inflamed eyelids. It may start with irritation due to trapped foreign objects or an insect bite. Symptoms may include dry and flaky eyelids, pus discharge and swelling of the eyelids which may prevent your cat from opening the affected eye. Treat it by soaking a cotton pad in warm water and press against the affected eye for 15 minutes. This should be done daily until the eye recovers.
8. Your cat may have cataracts.
Another reason why your cat may be keeping one eye closed is due to cataracts which often happens among senior cats. The causes may be diabetes mellitus and inflammation of the uvea which contains the iris, the ciliary body and the eye’s middle layer. Cataracts may resemble a cloudy blockage in your cat’s eye and may prevent light from entering the retina.
This leads to eyesight reduction and eventually blindness. Symptoms may include cloudy eye appearance and if caused by diabetes your cat may experience weight loss and excessive thirst and urination. Your vet may suggest surgery to treat the condition although most cats can survive with cataracts.
Cat breeds that are more prone to eye problems
Cat breeds that are considered brachycephalic are more prone to eye problems. Brachycephalic cats have shorter and rounder heads, short noses and have a unique skull shape. These cats are prone to dry eyes since tears do not easily flow from the eyes.
Here are some brachycephalic cat breeds that are more prone to eye problems:
- Persian
- Scottish Fold
- Munchkin
- Himalayan
- Burmilla
- Exotic Shorthair
- British Shorthair
Conclusion
If your cat is keeping one eye closed you should assess her condition at once. The common reasons why cats keep one eye closed may be due to an eye infection or irritation, glaucoma, corneal ulcer or conjunctivitis. It may also be due to inflamed eyelids, a trapped foreign object or cataract if you have a senior cat. While home treatment may be enough, if there symptoms do not go away you should bring your cat to the vet.
Image: istockphoto.com / Remains