Free tools Windows power users keep installed
One-click scans. No signup required.
A red, watery, squinting, or cloudy eye in a cat is a clue, not a diagnosis. The same outward sign can come from a minor surface irritation or from a condition that threatens sight, and different conditions often look alike to an owner. If your cat’s eye is painful, cloudy, injured, or has changed suddenly, arrange a veterinary examination without delay.
The eleven conditions below cover the main categories of feline eye disease described in veterinary educational guidance from Cornell University’s College of Veterinary Medicine and VCA Animal Hospitals. The number is an editorial choice, not a ranking. Neither source ranks these conditions by how often they occur, and no prevalence figures are given here, so read the order as a way of organizing the material rather than a measure of how common each problem is.
What a visible eye sign can point to
Owners usually notice a symptom before they know where the problem is. The table links common signs to the conditions that can produce them. Use it to decide how quickly to call your veterinarian, not to settle on a diagnosis.
| What you notice | Conditions that can produce it |
|---|---|
| Redness, excess tearing, or discharge | Conjunctivitis, dry eye, corneal ulceration, uveitis, corneal injury |
| Squinting, holding the eye shut, or light sensitivity | Conjunctivitis, corneal ulceration, corneal injury, uveitis, glaucoma |
| Cloudiness of the eye | Cataract, corneal ulceration, glaucoma, uveitis |
| Pupil or iris changes, or an eye that looks gradually larger | Glaucoma, uveitis |
| Ongoing irritation with an eyelid that appears to roll inward | Entropion |
| Difficulty navigating, bumping into objects, or hesitating in unfamiliar spaces | Retinal detachment, progressive retinal atrophy, cataract, glaucoma |
| A lump or mass in or around the eye | Eye and periocular tumors |
Several signs appear under more than one heading. That overlap is the reason an examination, and sometimes a test, comes before any treatment decision.
The Tool Desk
Outbyte PC Repair FREERepair Windows errors before they cause bigger problemsFix Now →Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →#1 Best Overall
- Committed To Quality: As pet parents too we understand how much your fur baby means to you. That's why at BestLife4Pets we're committed to providing top quality, Made in the USA
Eleven conditions, grouped by where they sit in the eye
Location largely determines what a veterinarian looks for and what is at stake. The conditions below are grouped by the part of the eye involved: the eyelids and tear film, the cornea, the lens, the inside of the eye, the retina, and tissue around the eye.
Eyelids and tear film
1. Conjunctivitis
Conjunctivitis is inflammation of the conjunctiva, the membrane that lines the eyelids and covers the outer surface of the eye. Signs include excess tearing, cloudy, yellow, or green discharge, redness, squinting, and light sensitivity. The inflammation can have an infectious cause, a noninfectious irritant, or another eye condition behind it. VCA Animal Hospitals advises veterinary examination for these signs because treatment depends on the cause.
2. Entropion
In entropion, an eyelid turns inward so that hairs rub against the eye and irritate the cornea, the clear front surface. VCA notes that it can be a congenital problem in some long-haired breeds. Persistent corneal irritation is a reason for a veterinarian to check eyelid position as well as the surface of the eye.
Rank #2
- Immune Support for Cats: Our L-Lysine for cats is specially formulated to support your cat's overall well-being. It promotes normal eye function and respiratory health while strengthening the immune system to help manage common feline issues such as sneezing, runny nose, squinting, and watery, inflamed eyes
- Premium Ingredients: Our Lysine drops for cats are enriched with a variety of natural ingredients and essential vitamins to promote feline health. Key components include L-Lysine HCl for immune support, Astragalus and Codonopsis for vitality, Atractylodes Macrocephala for digestive health, Burdock Seed for skin and coat nourishment, and a blend of Vitamins for overall well-being
- Super Delicious: Our lysine cat treats is made into a delicious chicken flavor that even picky fur babies will absolutely love. It is suitable for cats of any age, breed, and size, helping to keep your furry friend healthy and happy with our irresistible formula
- Best Trust for Cats: Our lysine supplement for cats uses safe ingredients that are free from grains, alcohol, and gluten, and contains no additives or harmful chemicals. This makes it completely safe for all cats
- No More Worries: When using our lysine liquid for cat, you don't have to worry about messy powders, annoying capsules, tablets, or hard-to-chew solids. They can be used directly or mixed with food, water, or milk, and even fed directly to your cat
3. Dry eye (keratoconjunctivitis sicca, KCS)
Dry eye develops when tear production is inadequate. Affected eyes can be painful and red, with thick yellowish mucus and a dull surface. Without enough tears, ulcers can form, and chronic scarring can follow. A Schirmer tear test measures tear production. Treatment is directed by a veterinarian and may need to continue long term.
Recommended Free Tools
Cornea
4. Corneal ulceration
A corneal ulcer is a loss of cells from the outer layer of the cornea. Causes include scratches, ingrown eyelashes, trapped debris, caustic chemicals, and infection. Cornell University’s College of Veterinary Medicine identifies recurrent feline herpesvirus infection as a frequent cause. Signs can include inflammation around the eye, discharge, cloudiness, light sensitivity, squinting, and rubbing at the eye.
Veterinarians commonly use fluorescein dye to reveal the ulcer. Thomas Kern, DVM, of Cornell’s College of Veterinary Medicine, explains the principle in Corneal Ulcers:
Rank #3
- Taurine for Cats: This cat supplies includes taurine and lutein to help cat retinal health and preventing vision degeneration. Lutein acts as a natural blue light filter to protect delicate eye cells, while the powerful antioxidant Astaxanthin supports overall eye resilience. The added cat vitamins for indoor cats (cat vitamins and supplements) is good for cat immune support.
- Support Vision & Antioxidant Support: This vision care bites, as well as taurine supplement for cats are specially formulated to support sharp vision and long-term eye health in cats. This cat treats for indoor cats provides powerful antioxidant protection to help combat oxidative stress and cellular damage. An excellent cat essentials your cats should have!
- Delicious Chicken Flavor: Cats love the tasty chicken taste! These vision and taurine supplements for cats make skin health and immune support easy—even for picky eaters. No more struggling to give supplements; may contribute to overall wellness.
- Great Value, Long-Lasting Supply: This taurine treats for cats has big jar and amount. Suitable for cats of all breeds and ages (3+ months).
- Healthy Cat Treats: This cat health supplies & kitten treats for indoor kittens does not contain corn, wheat, soy, or artificial additives. Rigorously tested for purity and effectiveness.Trusted for your cat’s health and peace of mind.
“If an ulcer is present, the dye will bind to any damaged tissue, leaving a clearly visible greenish coloration on the ulcerated area.”
Deep ulcers can perforate and threaten the eye itself. Self-trauma, such as rubbing, can make an ulcer worse, so a veterinarian may require an Elizabethan collar until it heals. The collar is a protective measure whose use is set by the veterinarian. It does not diagnose or treat the ulcer.
5. Corneal laceration and other eye injury
A cut to the cornea is a traumatic injury that can be blinding. Cornell says early diagnosis improves the chance of effective treatment. Treat any suspected eye injury as urgent and contact a veterinarian rather than waiting to see whether it settles.
Rank #4
- Cat Immune Support - Coco and Luna L-Lysine for cats helps support a strong immune system and eye function providing cat vitamins for older cats and kittens alike.
- Respiratory Health - Our formula promotes normal respiratory function and health which can help fight against issues such as sneezing, watery and inflamed eyes, and runny noses.
- Easy to Serve Powder - Our formula has the best natural ingredients, adjusted for cats in an easy to serve format that can be given with food or as a daily treat.
- A Brand You Can Trust - We understand how much your pet’s health and wellbeing mean to you, so our products are manufactured in FDA-registered facilities that are NSF and GMP-certified in the USA.
- Made in the USA from US and Globally Sourced Ingredients - All our products are made in the USA and are veterinarian approved as well as hypoallergenic. Our L-Lysine powder helps bring your cat nose relief and may help with sneezing and other cold-like symptoms.
Lens
6. Cataracts
A cataract is clouding of the lens, the structure behind the iris that focuses light onto the retina. When the lens clouds, it can block light and impair vision. Clouding of the lens and clouding of the cornea’s surface can look similar to an owner, and an owner cannot reliably tell which structure is affected without an examination. Published guidance describes cataracts mainly by their effect on sight, so cause and management are decided at the veterinary visit.
Inside the eye
7. Glaucoma
Glaucoma develops when fluid draining from inside the eye fails. The resulting rise in pressure can injure the optic nerve. Cornell’s guidance on feline glaucoma lists cloudiness, gradual enlargement of the eye, squinting, and a dilated pupil that does not react normally among the possible signs. A veterinarian measures intraocular pressure with a tonometer. Once glaucoma has damaged the optic nerve, that damage is not reversible, and vision loss may progress.
8. Uveitis
Uveitis is inflammation of the uvea, the pigmented middle layer of the eye. It is associated with infectious and other systemic causes, so an underlying illness may need investigation. The eye may be red or cloudy, and the pupil may change. Uveitis can resemble glaucoma, and measuring intraocular pressure is how a veterinarian distinguishes the two. Treatment addresses pain, inflammation, and any underlying illness. Complications can include glaucoma and retinal detachment.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
Best Value
- KEEP BAD DAYS AT BAY: Itchy. Sneezy. Wheezy. We know cat allergies are no fun—for them or for you. That’s why our I-Lysine supplement for cats helps support a strong immune system, soothe itchy skin, and maintain clear breathing. It’s used to relieve sneezing, runny noses, and watery eyes while helping balance your cat’s gut and digestive health. Give it directly as a crunchy, creamy treat or sprinkle it on their food for easy daily wellness at home or after outdoor adventures.
- THE INSIDE STORY: Formulated with science-backed ingredients like L-Lysine, Quercetin, and Colostrum, this cat allergy relief supplement is capable of strengthening immune and respiratory function from the inside out. Antioxidants defend against seasonal irritants, while omega fatty acids help calm skin and coat discomfort. It’s a vet-approved allergy solution cats love—made to keep your little one healthy through every season.
- SECOND TO NONE: Pet Honesty’s Cat Immune Support Lysine treats are trusted by vets and loved by cats everywhere. Our allergy relief chews are used by cat parents who want real results, real relief, and real transparency. Proudly the #1 vet-approved allergy support brand on Amazon and in Pet Specialty*, we create supplements that deliver visible improvements in your pet’s comfort and well-being.
- DROOL-WORTHY TASTE: 4 out of 5 cats can’t resist the crunchy-creamy texture and savory chicken flavor of our Cat Immune Support Lysine treats. Whether sprinkled on kibble or served as a standalone treat, they make daily immune and respiratory care feel like snack time. Perfect for picky eaters or for use alongside probiotics and daily multivitamins to support complete feline wellness.
- THE HONEST DIFFERENCE: Our products are made with clean, science-backed ingredients for results you can trust, & with no fillers, artificial preservatives, colors, or flavors, you'll have no doubt your cat is getting the best. Proudly supporting pets in need nationwide & using recycled plastic in our packaging, there's also no doubt that we're committed to doing our best. -- All products are manufactured in the U.S.A. | NASC Member Company
Retina
9. Retinal detachment
In retinal detachment, the retina separates from the tissue beneath it. Cornell associates the condition with high blood pressure, overactive thyroid, and kidney disease, so a veterinarian may check for these when a detachment is found. Prompt treatment can restore some vision, but permanent blindness is common. A cat already diagnosed with one of these systemic conditions that suddenly struggles with vision should be examined without delay.
10. Progressive retinal atrophy
Progressive retinal atrophy is degeneration of retinal tissue that compromises its function. Cornell lists it among disorders that can impair or destroy vision. Published guidance on this condition is brief and does not set out diagnostic or treatment steps, so testing and management depend on your veterinarian’s examination.
Tissue around the eye
11. Eye and periocular tumors
Tumors can develop inside the eye or in the tissue immediately around it. They may be benign or malignant, and appearance alone does not reveal which. Treat a new mass, or any eye change that persists, as a question for a veterinary examination.
Tests your veterinarian may use
Which tests apply depends on the signs and the examination. The table lists the tests named in veterinary guidance for these conditions.
| Test | What it establishes | Where it comes up |
|---|---|---|
| Eye examination | Baseline assessment of the eyelids, surface, and structures the veterinarian can see | First step for all eleven conditions |
| Fluorescein staining | Damaged corneal tissue takes up the dye and shows as green | Corneal ulceration and other corneal damage |
| Schirmer tear test | How much tear production the eye has | Dry eye |
| Tonometry (intraocular pressure measurement) | Pressure inside the eye, measured with a tonometer | Glaucoma, and distinguishing glaucoma from uveitis |
| Systemic workup | Whether an underlying illness, such as high blood pressure, thyroid disease, kidney disease, or infection, is present | Where indicated; especially uveitis and retinal detachment |
When to call your veterinarian
VCA Animal Hospitals advises immediate veterinary examination for excessive tearing, abnormal discharge, redness, squinting, or a cat holding the eye shut. Contact your veterinarian promptly for any of the following:
- An eye that is painful, or squinting that does not resolve
- Redness together with abnormal discharge
- Cloudiness in one or both eyes
- Visible injury, or any suspected injury to the eye
- Pupils of unequal size, or an eye that looks enlarged
- A sudden change in vision, or new difficulty moving through familiar space
Cornell’s Thomas Kern, DVM, urges owners to watch for behavioral or physical signs of a vision problem and to report them to a veterinarian without delay. When you call, give a clear account of when the signs began, whether one or both eyes are affected, any known injury, and any other diagnosed conditions, particularly high blood pressure, thyroid disease, or kidney disease, because these are linked to some of the conditions above.
Quick Recap
What to avoid at home
- Do not use leftover prescription medication or medicine prescribed for an earlier eye episode. VCA warns that medication used for a previous conjunctivitis episode may not help and may be harmful.
- Do not use human eye drops, supplements, or home remedies in place of a veterinary diagnosis.
- Do not choose treatment based on how the eye looks. Treatment follows diagnosis, and the same visible sign can have different causes.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
