Eyes

A cat's eyes are expressive, beautiful — and remarkably good at hiding a problem until it's become significant. Cats instinctively mask discomfort, so by the time you notice something looks different, your cat may have been uncomfortable for a while. The encouraging thing is that most eye conditions respond very well to treatment when caught early. Getting into the habit of glancing at your cat's eyes regularly is one of the simplest things you can do to protect their long-term health and vision.

What a Healthy Cat's Eye Looks Like

Knowing what's normal makes it much easier to spot when something isn't. A healthy cat's eye should be clear and bright, with no discharge or cloudiness. The pupils should be roughly equal in size and respond to changes in light. The tissue around the eyeball — the conjunctiva — should be a pale, healthy pink, not red or swollen. The white of the eye should actually be white.

Cats have a third eyelid — a pale membrane tucked into the inner corner of each eye. In a healthy, relaxed cat, this is barely visible. If it starts to protrude noticeably, covering part of the eye, it's usually a sign that something needs attention — whether that's an eye condition directly, or sometimes an underlying illness elsewhere in the body.

When should it be done?

The British Veterinary Association and the British Small Animal Veterinary Association both recommend neutering from around 16 weeks of age. This is because female cats can start getting pregnant from around four months old — and the numbers add up faster than most people realise. Cats can have three or four litters per year, which can mean as many as 20 kittens from a single unneutered female annually.

Your vet may advise waiting slightly longer if your kitten is particularly small or unwell. If you're unsure, just ask — they'll guide you based on your individual cat.

Signs That Something Needs Attention

Eye problems can present in many ways, and some are more urgent than others. Signs to look out for include:

Squinting or keeping one or both eyes partially closed
Excessive blinking or pawing at the eye
Discharge — whether watery and clear, or thick and coloured
Redness or swelling around the eye
Cloudiness or haziness on the surface of the eye
Pupils of unequal size
The third eyelid becoming visible or covering part of the eye
Sensitivity to light — your cat avoiding bright areas
Any visible change in the colour or appearance of the eye

As a general rule: if your cat's eye looks different from normal, contact your vet. Eyes are one area where it really doesn't pay to wait and see. What looks like a minor irritation can deteriorate quickly — sometimes within 24 to 48 hours — and early treatment can make a significant difference to the outcome.

The Most Common Eye Conditions

Conjunctivitis is the most frequently seen eye problem in cats — an inflammation of the membrane lining the eyelids and surrounding the eye. It can be caused by viral or bacterial infections, allergies, or irritants, and often occurs alongside upper respiratory infections. Signs include redness, swelling, and discharge ranging from clear and watery to thick and yellowish-green. It can affect one or both eyes. In cats, the feline herpes virus is one of the most common underlying causes, and can recur throughout a cat's life, particularly during periods of stress or illness.

Corneal ulcers are injuries to the clear outer surface of the eye — essentially a scratch or wound on the cornea. They're painful, and cats will typically squint, blink excessively, or paw at the affected eye. The surface of the eye may appear cloudy or hazy. Corneal ulcers can develop and worsen very rapidly, so prompt veterinary attention is essential. Treatment usually involves antibiotic or antiviral eye drops, depending on the cause.

Uveitis is inflammation inside the eye itself. It can be caused by infection, trauma, immune system disorders, or sometimes an underlying systemic illness. Signs include squinting, redness, a cloudy or discoloured appearance, and a noticeably small pupil in the affected eye. Because uveitis often presents at a late stage — by which point it may look like a different condition entirely — it can be easy to miss. It requires urgent treatment to prevent permanent damage.

Glaucoma occurs when pressure inside the eye builds to a damaging level. It is painful, can progress quickly, and is a veterinary emergency. A cat with glaucoma may have a visibly enlarged or bulging eye, cloudiness, redness, and obvious signs of pain or distress. Immediate veterinary care is needed to protect the cat's vision.

Eye Conditions Linked to Other Illnesses

It's worth knowing that the eyes can sometimes reflect what's happening elsewhere in the body. A number of systemic conditions — including high blood pressure, kidney disease, hyperthyroidism, and certain infections — can cause eye symptoms as a secondary effect.

Retinal detachment, for example, is a condition where the back of the eye separates from the tissue behind it. In cats, it is most commonly associated with high blood pressure (hypertension) — which itself is often linked to kidney disease or an overactive thyroid. A cat experiencing sudden vision loss may bump into furniture, seem disorientated, or become hesitant and unsure of their footing.

This is one of the reasons it's so important to see a vet rather than attempting to manage eye symptoms at home. What appears to be a straightforward eye problem can occasionally be the first visible sign of a condition requiring broader investigation and treatment.

What Your Vet Will Do

Your vet will examine your cat's eyes thoroughly, often using an ophthalmoscope to look at the structures inside. They may carry out specific tests depending on what they find — a fluorescein stain test, for example, is a simple and painless way to check for corneal ulcers, as the stain highlights any damage to the surface of the eye.

Treatment depends entirely on the diagnosis and may include antibiotic, antiviral, or anti-inflammatory eye drops or ointment, pain relief, treatment for any underlying condition, or — in more complex cases — referral to a veterinary ophthalmologist.

One important note: never use eye drops or treatments on your cat unless they have been prescribed for that specific cat and that specific condition. Using the wrong product — or a product prescribed for a previous, different eye problem — can make things significantly worse.

When To Act Immediately

Most eye problems warrant a prompt appointment rather than an emergency dash — but there are situations where you should contact your vet the same day, or immediately if out of hours:

Your cat is in obvious pain — crying, hiding, refusing food, or very reluctant to move
The eye looks visibly swollen, bulging, or has changed shape
There has been a sudden change in vision — your cat bumping into things or seeming disorientated
Pupils are very unequal in size
There is significant discharge or the eye appears to be closing completely
Your cat has had any trauma to the head or face

When in doubt, call your vet and describe what you can see. They will tell you how urgently your cat needs to be seen. Eyes are precious — and a cautious phone call is always the right instinct.