Cats should have bright, alert, and wide-open eyes as they are born hunters.
Unless they are dozing, keeping one eye closed or squinting could indicate that they are suffering from discomfort.
This could be a case of an occasional and temporary irritation though it could be something more serious like an eye infection.
There are several eye infections to look out for so it is worth knowing the symptoms and treatments before they get worse.
That eye could be red and look itchy which could suggest pink eye, otherwise known as conjunctivitis and the iris of your cat could indicate a cataract or an ulcer.
If the cat’s eye simply looks swollen then this could be glaucoma.
Take the time to look at your cat’s eyes as they should be matching and look bright.
If your cat is scratching and pawing at one eye quite regularly then you may want to get it checked out by a veterinarian.
In this guide, we will look at the potential reasons why a cat is keeping one eye closed or squinting and detail the eye infections.
We will also look at how to examine your cat’s eyes, how to remove trapped foreign objects, and the symptoms to look out for.
The Potential Reasons Why A Cat Is Keeping One Eye Closed Or Squinting
There are numerous reasons why a cat may keep an eye closed or look to be squinting.
These could be listed as an illness such as glaucoma, blepharitis, or conjunctivitis.
It could also be due to a cataract, an ulcer on the cornea, a typical eye infection, eye irritation, or simply a foreign object that has gotten trapped in a cat’s eye.
The eye remains a very important yet fragile organ for a cat.
Just a single scratch can soon turn into an eye infection so it is worth keeping an eye out for any unusual behavior.
Only a veterinarian can perform an eye examination and any issues should be detected and corrected as soon as possible.
Eye infections can soon become irreversible eye damage when untreated and even result in blindness.
The Eye Infections
It is worth going into more detail about the eye infection as they can be different in their symptoms.
If you see one of your cat’s eyeballs protruding or your cat constantly squints, winks, or blinks then that should be treated.
Should your cat seem to be producing an excessive amount of tears or has visible redness around the eye, or even in it, then this should also be looked at.
Most eye infections can be treated simply and quickly with some prescription eye drops that are antibacterial from a veterinarian, but do not use human eye drops.
If you do not apply antibacterial eye drops then the infection can manifest into glaucoma.
This is where a cat is prevented from draining fluid from its eyes as it typically would through their tear ducts.
Once the cat cannot drain that fluid, the pressure begins to build up.
Eventually, the cat will be unable to fully open its eye and it can be incredibly painful.
Spotting the first signs of glaucoma should prevent this initial discomfort from getting even worse as it can be treated quickly.
You do not want your cat to lose an eye so look out for any visible swelling in a cat’s eye and whether your cat claws and paws at a specific eye.
The pupils may appear dilated and there could be a watery discharge with a cloudy and discolored iris.
One of the huge problems with glaucoma is that it cannot be reversed or cured and needs to be continually managed.
Pink Eye (Conjunctivitis)
Another common eye infection is pink eye, which is also known as conjunctivitis.
This is where a cat’s eye can become red and swollen due to inflammation.
Your first indication of this infection should be when your cat begins to claw and then rub its eye.
The eye infection is typically due to another cat though it can be caused by an allergy.
Again, the solution to the pink eye is to use eye drops, specifically anti-inflammatory ones.
With proper treatment, your cat should make a full recovery within just two days.
There should be an argument that cataracts are to be accepted as simply an indication that a cat is getting old.
As part of the aging process, you can expect cataracts to appear on an old cat and they simply appear to be cloudy blockages in an eye.
Cataracts will go some way to prevent some light from reaching the retina which will, in turn, reduce a cat’s eyesight.
Eventually, you can expect a cat suffering from cataracts to become blind yet it can survive.
Thankfully, cats can use their other senses and their whiskers to detect their surroundings rather like a human uses a guide.
Cataracts can also be removed using a surgical procedure.
Another visible eye infection for your cat may be the development of corneal ulcers.
When layers of the cornea are depleted they can cause various symptoms including a film over the eye.
Further symptoms can include an excessive amount of ocular discharge and an increased sensitivity to light which may cause your cat to squint an eye when in a bright room.
These corneal ulcers can be caused by infection or even trauma and the treatment would be antibiotic eye drops though a deep ulcer may require surgery.
When a cat’s eyelid becomes chronically inflamed, that typically means that blepharitis has set in.
This eye infection starts with irritation which can be caused by just a foreign object getting trapped or it could be an insect bite.
As the infection gets worse, the cat’s eyelid can become increasingly dry and flaky, then you may begin to notice pus leaking out.
Soon enough, the cat’s eyelid will swell up and result in the cat being unable to fully open its eye.
You can treat blepharitis at home just by soaking a cotton pad in some warm water and then gently holding it by your cat’s infected eye for around 15 minutes.
Repeat this procedure daily and the swelling should begin to come down.
However, you should look to remove the primary cause of the infection first which could be a foreign object.
For that, you would need some antibiotic eye drops.
Blepharospasm is an inflammation that affects both the conjunctival membranes and the eyelids.
Both swell up which forces the cat to squint and if both inflammations cause severe damage then that can result in conjunctivitis and blepharitis.
The condition can be caused by bacterial infections and entropion which is a congenital eyelid abnormality.
Once your cat begins blinking quickly, it may not be too long before one eyelid is closed.
Should your cat be suffering from a viral infection or a bacterial infection, it may have runny eyes with a green discharge.
The infections go by various names including cat flu, influenza, and viral rhinitis.
The bacteria that causes the most concern are mycoplasma, Bordetella bronchiseptica, and Chlamydophila felis which can be complicated.
There is also feline herpesvirus which can result in feline viral rhinotracheitis which affects the conjunctiva and causes swollen eyelids with a watery then pus-like discharge.
Feline calicivirus can cause an infection with pretty much the same symptoms you will find in feline herpesviruses like eye discharges, squinting, blepharospasm, and conjunctivitis.
Chlamydophila felis can also cause feline pneumonitis which will mean inflamed eyes that become red and bloodshot.
There may also be a discharge from the eyes themselves while this condition can manifest into severe conjunctivitis.
If your kitten is suffering from feline herpesvirus then they may have the condition known as symblepharon.
This is where the conjunctival tissue glues itself to another piece of tissue or the cornea of the eye itself.
It does seem to be only kittens that are only a few weeks old that suffer from the condition that makes it appear that they are squinting.
The symptoms should relieve themselves yet surgical treatment may be necessary to separate those glued tissues.
Once the front part of the interior of a cat’s eye has become inflamed then your cat may have uveitis.
The condition concerns the area between the cornea and the iris so the eyes may look cloudy and hazy.
You may even notice some red or white-yellowish sediment at the bottom of the eyes.
Uveitis is typically caused by another illness, typically diabetes, an auto-immune condition, high blood pressure, or even cancer which is worth checking out.
Simple Eye Irritation
The eye infection may simply be a case of eye irritation.
If the cat has to endure an environment filled with tobacco smoke, dust, cleaning chemicals, and strong fragrances then this can irritate their eyes.
The eyes may become irritated resulting in squinting and rubbing of any affected eyes.
To relieve their pain, rinse out the affected eyes with an eye-wash solution.
How To Examine Your Cat’s Eyes?
Try to gently hold your cat while you take a closer look at their eyes, you may even see a foreign object which can be removed by a veterinarian.
If you spot various symptoms then it may be easier to diagnose the problem and get your hands on the right medication.
As well as the condition of a specific eye, take a specific look at the cat’s pupils and their eyelids.
If the pupils look mismatched then this could be a condition known as anisocoria.
Try to look out for the iris as this can be discolored too which would help to indicate a condition known as melanosis.
If your cat is particularly sensitive due to old age then this is a common ailment and is typically harmless.
You may even see brown spots which can be likened to liver spots.
Once a foreign object becomes trapped in your cat’s eyes then it can soon lead to an eye infection.
You may not see the trapped foreign object yet if your cat is squinting, producing an excessive amount of tears, rubbing its face on the floor, or pawing at its eye then you should be concerned.
These actions would indicate that a foreign object is trapped in your cat’s eye and that could be a small stone, some grit, dust, or even ingrown hair or fur.
How To Remove Trapped Foreign Objects In Your Cat’s Eyes?
Identifying that your cat has a foreign object trapped in its eye is one thing, removing it is quite another.
Try to remove the object by washing your cat’s eyes with a mixture of warm water with saline solution.
This can be applied with a cotton pad, do not try to use tweezers to remove the foreign object as you can easily injure their eye.
Once the eye is washed, that irritation should pass.
The Symptoms To Look Out For In A Cat’s Eyes
There are various symptoms that you should look out for that could be early indications of eye infections.
Before your cat begins to close one day or squint, look out for red rings around the eye’s edges.
If your cat is blinking with one eye consistently more than the other then this is another symptom to look out for.
Red Rings Around A Cat’s Eyes
Your cat should not have red rings around their eyes and this is a surefire sign of an eye infection.
It could be that your cat has suffered from minor ocular trauma which could be something as trivial as being poked in the eye.
They could have accidentally scratched themselves while grooming or just walked into a branch.
A mild infection may relieve itself all on its own by your cat blinking more than normal to reduce the redness though it could lead to conjunctivitis.
One Eye Blinking More Than The Other Eye
Even cats blink but if you notice they are just blinking with one eye then this could be because there is a foreign object trapped there.
However, a slow cat blink is typically a sign of affection known as a ‘cat kiss’.
However, quicker blinks tend to indicate irritation with the blinking being the cat’s method of trying to remove a trapped foreign object.
Preventing Cats From Suffering Eye Infections
Unfortunately, cats will be cats and they can occasionally cause their own problems.
When they are out and about they can injure themselves with a branch or just from their typical scratching.
However, eye infections can be a sign of old age or be genetic in nature which cannot be prevented.
Even keeping a cat indoors may not prevent it from suffering eye infections though it may be beneficial to keep it away from other cats to prevent possible fighting.
As soon as your cat’s eyes become less than bright, you should want to check them out.
A lot of eye illnesses and infections can be caught early before they cause some real damage.
If you see any sediment or discharges then take a closer look at your cat’s eyes.
If they are keeping one eye closed and squinting then it might be time to visit a veterinarian.
Frequently Asked Questions
Why Does It Appear That My Cat Is Sleeping With One Eye Open?
Cats can seem vulnerable, especially when they are trying to sleep as they are naturally cautious.
That could be a reason for appearing to sleep with an eye open but that is not the case.
There is a transparent third eyelid for cats which is known as the nictating membrane which rests below the conjunctiva in the corner of an eye.
That eyelid closes while sleeping and helps keep a cat alert so it just appears that they are sleeping with an eye open.
Which Cat Breeds Are The Most Prone To Problems With Their Eyes?
Several eye problems can be traced down to genetics and a cat’s breed may be one cause for concern.
For instance, brachycephalic cats are increasingly prone to ocular problems and that covers many cat breeds.
From the Selkirk Rex to the Scottish Fold as well as Persian, Munchkin, and Himalayan cats.
That category also includes the Exotic Shorthair cats, Burmillas, and the British Shorthair.
The brachycephalic cat can be identified by their unique skull shape and rounder, shorter heads.
Their propensity for eye problems is typically down to the folds of their skin being more prone to trapping foreign objects and their comparative lack of tears.
That simple lack of tears means dried-out and inflamed eyes.
Dr. Linda Simon MVB MRCVS is a locum veterinary surgeon who has worked in London for the past 8 years. She graduated top of her class in small animal medicine from UCD, Dublin. She is currently a member of the Royal College of Veterinary Surgeons. Linda is the resident vet for Woman magazine and a frequent contributor to People’s Friend Magazine, the Dogzone website, Vet Help Direct and Wag! Linda also writes content for the CVS veterinary group, Vetwriter and a number of other establishments.