Cat Squinting One Eye: Causes & What to Do

Quick Answer
  • Squinting usually means the eye is painful, irritated, or both. Common causes include a scratch on the cornea, conjunctivitis, feline herpesvirus flare-ups, a foreign object, uveitis, glaucoma, or eyelid problems.
  • Same-day veterinary care is recommended if the eye looks cloudy, very red, swollen, partly closed, has yellow-green discharge, or your cat is rubbing at it. Eye trauma and chemical exposure are emergencies.
  • Do not use human eye drops unless your vet specifically tells you to. Some medications can make certain eye problems worse, especially if a corneal ulcer is present.
  • At home, keep your cat indoors, prevent rubbing, and gently wipe discharge with sterile saline on gauze. If squinting lasts more than a few hours or returns, schedule an exam.
Estimated cost: $90–$450

Common Causes of Cat Squinting One Eye

Squinting in one eye is called blepharospasm, and in cats it often means the eye is painful. One of the most common causes is a corneal ulcer or scratch. This can happen after rough play, a cat fight, rubbing the eye, or a bit of debris getting trapped under the eyelid. Corneal ulcers are very uncomfortable, and many cats keep the eye tightly shut. Feline herpesvirus can also trigger recurrent eye disease, including conjunctivitis and corneal irritation.

Another common cause is conjunctivitis, which is inflammation of the tissues around the eye. Cats with conjunctivitis may squint, blink more, and have watery, mucus-like, or darker discharge. Viral upper respiratory infections, especially herpesvirus, are a frequent reason. Some cats also develop squinting from eyelid problems like entropion, where the eyelid rolls inward and hairs rub the cornea.

Less common but more urgent causes include uveitis and glaucoma. Uveitis is inflammation inside the eye and can be linked to infection, immune disease, trauma, or other systemic illness. Glaucoma causes increased pressure in the eye and can threaten vision quickly. A cat may also squint because of foreign material, chemical irritation, or trauma. Because several very different problems can look similar at home, your vet usually needs to examine the eye to tell them apart.

When to See the Vet vs. Monitor at Home

A cat who is squinting one eye should usually be seen the same day or within 24 hours, even if they still seem bright and are eating. Eye pain can escalate quickly, and some conditions that start with mild squinting can lead to corneal damage or vision loss if treatment is delayed. If your cat has a history of feline herpesvirus, a flare-up is possible, but that still does not rule out an ulcer or another painful problem.

See your vet immediately if the eye is cloudy, blue-white, very red, swollen, bulging, bleeding, or suddenly looks larger than the other eye. Immediate care is also important if your cat cannot open the eye, is pawing at the face, had a known injury, was exposed to shampoo or chemicals, or seems suddenly less able to see. Kittens, flat-faced breeds, and cats with repeated eye issues should be checked promptly.

You may be able to monitor briefly at home only if the squinting is very mild, started recently, there is no redness or cloudiness, and your cat is otherwise acting normal. Even then, if it lasts more than a few hours, comes back, or any discharge develops, contact your vet. Avoid a wait-and-see approach if you are unsure. Eye problems are one of the situations where early treatment often means fewer tests, lower cost range, and a better outcome.

What Your Vet Will Do

Your vet will start with a history and a careful eye exam. They will look for discharge, redness, corneal cloudiness, eyelid abnormalities, pupil changes, and signs of trauma. Many cats also need a fluorescein stain, a dye test that highlights corneal ulcers or scratches. Depending on the exam, your vet may also check tear production and measure eye pressure with tonometry, which helps screen for glaucoma or support a diagnosis of uveitis.

If your cat has recurrent eye disease, your vet may discuss feline herpesvirus as a likely contributor. If the eye looks inflamed inside, or if there are signs of a deeper problem, they may recommend additional testing such as bloodwork, infectious disease screening, or referral to a veterinary ophthalmologist. The exact plan depends on whether the problem appears to be on the eye surface, inside the eye, or related to a whole-body illness.

Treatment is based on the cause. Options may include lubricating drops or ointment, antibiotic eye medication when indicated, pain control, an e-collar to prevent rubbing, and follow-up staining or pressure checks. Some cats need oral medication or more advanced procedures if the ulcer is deep, the pressure is abnormal, or the eye has been injured. Your vet will match the plan to your cat's diagnosis, comfort, and your household's goals and budget.

Treatment Options

Spectrum of Care means you have options. Here are treatment tiers at different price points.

Budget-Conscious Care

$90–$220
Best for: Mild to moderate squinting without major trauma, severe cloudiness, or suspected glaucoma, especially when your cat is stable and the exam suggests a surface problem.
  • Office exam
  • Basic eye exam
  • Fluorescein stain to check for a corneal ulcer
  • Targeted medication trial when findings are straightforward, such as lubricant or an ophthalmic antibiotic if appropriate
  • E-collar recommendation and home monitoring plan
  • Short recheck if symptoms are not improving
Expected outcome: Often good when the cause is a mild corneal scratch, uncomplicated conjunctivitis, or irritation caught early.
Consider: Lower upfront cost range, but fewer diagnostics may miss deeper disease such as uveitis, glaucoma, or a hidden foreign body. Follow-up is important if the eye is not improving quickly.
Most Common

Recommended Standard Treatment

$180–$450
Best for: Most cats with one-eye squinting, especially if there is redness, discharge, recurrent symptoms, or uncertainty about the cause.
  • Office exam
  • Fluorescein stain
  • Tonometry to measure eye pressure
  • Tear testing if dryness is a concern
  • Prescription eye medication tailored to findings
  • Pain control when indicated
  • E-collar
  • Recheck exam in 3-7 days, or sooner if needed
Expected outcome: Good to fair, depending on the diagnosis. Many surface eye problems improve well with prompt treatment, while uveitis or herpes-related disease may need closer follow-up.
Consider: More complete than conservative care and often the best balance of information and cost range, but still may not identify every underlying systemic cause if the eye disease is part of a larger illness.

Advanced / Critical Care

$500–$2,500
Best for: Cats with severe pain, deep ulcers, abnormal eye pressure, trauma, suspected glaucoma, recurrent nonhealing disease, or risk to vision.
  • Emergency exam or specialty ophthalmology referral
  • Advanced diagnostics for complex eye disease
  • Sedated exam if pain or spasm prevents a full evaluation
  • Bloodwork and infectious disease testing when internal eye inflammation is suspected
  • Corneal debridement, grafting, or other surgery for deep/nonhealing ulcers
  • Hospitalization or intensive monitoring for severe trauma, glaucoma, or vision-threatening disease
Expected outcome: Variable. Some cats recover vision and comfort well with rapid intervention, while others may have scarring, chronic disease management, or permanent vision loss despite treatment.
Consider: Highest cost range and more intensive care, but may be the most appropriate option when the eye is at risk or when earlier-tier care has not solved the problem.

Cost estimates as of 2026-03. Actual costs vary by location, clinic, and individual case.

Questions to Ask Your Vet About Cat Squinting One Eye

Bring these questions to your vet appointment to get the most out of your visit.

  1. What is the most likely cause of the squinting based on today's exam?
  2. Does my cat have a corneal ulcer, conjunctivitis, uveitis, glaucoma, or something else?
  3. Which eye tests are most important today, and which ones can wait if I need to manage the cost range?
  4. Are the medications meant to treat pain, infection, inflammation, lubrication, or all of these?
  5. Is feline herpesvirus a possible factor in my cat's eye problem or repeat flare-ups?
  6. What warning signs mean I should come back sooner than the planned recheck?
  7. Should my cat wear an e-collar to prevent rubbing, and for how long?
  8. If this does not improve, when would referral to a veterinary ophthalmologist make sense?

Home Care & Comfort Measures

Keep your cat indoors and calm until your vet visit. Prevent rubbing or scratching at the eye, since self-trauma can turn a mild surface injury into a deeper ulcer. If your cat tolerates it, an e-collar can help protect the eye. You can gently wipe away discharge with sterile saline and clean gauze, using a fresh piece each time. Do not press on the eye.

Do not use leftover pet eye medication, human eye drops, redness relievers, or steroid-containing products unless your vet has examined the eye and told you exactly what to use. Some medications are unsafe if a corneal ulcer is present. Avoid trying to flush the eye aggressively at home unless your vet has directed you to do so after a mild irritant exposure.

Watch for worsening redness, cloudiness, swelling, discharge, hiding, reduced appetite, or trouble navigating. These changes mean the problem may be more painful or more serious than it first appeared. If your cat is squinting one eye for more than a few hours, or if the symptom keeps returning, schedule an exam with your vet rather than relying on home care alone.

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