Cat Eye Infections: Causes, Symptoms & Treatments

Written By
Reviewed by
Dr. Sarah Wooten, DVM
7 min read

Updated - Mar 6th, 2022

A cat’s eyes are beautiful, expressive, and provide important indicators when they aren’t feeling well. Eye infections in cats are very common, with some infections easily clearing up on their own, and some showing signs of a more serious illness. Knowing the most common causes and symptoms for cat eye infections can help you prevent them – or quickly deal with them – if you ever find your cat looking at you with weepy, red, or gunky eyes.

Let’s start by looking at the anatomy of cat eyes:

Cat eyes are very similar to human eyes with some very cool differences.

First, cats have elliptical pupils, allowing them to adjust to changes in light much quicker than we can with our round pupils. 

Second, cats only need 1/6th of the light we do because they have a gel-like substance in the back of their eye called a tapetum lucidum (Image). The gel reflects light, allowing them to see better at night.

The third cool feature of a cat’s eyes is the Nictitating membrane a.k.a. “the third eyelid” – its purpose is to protect the eye from injury when cats are roaming or hunting. It protects the eye when there’s inflammation by partially closing, and it can also cover the eye when a cat is sleeping or not feeling well.

With these complex anatomy additions, your cat’s eyes are critical for navigating their world – making it all the more important to keep them healthy.

How will I know if my cat is having eye problems?

A healthy cat’s eyes are clear, bright, the pupils are both the same size, and there’s no excessive discharge, redness, or puffiness. When you look at your feline friend’s eyes, there should be no cloudiness and you should not see the third eyelid. If your kitty’s eyes don’t look as healthy as they should, they could be suffering from an eye infection.

Let’s look at some common types of eye infections in cats, and their causes. 

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Allergies: If your cat is sneezing, this could be why.

Cats get allergies just like dogs and humans do. Allergies can come from many sources and need a vet’s diagnosis to confirm them.

Common allergens:

  • Fleas
  • Pollens
  • Chemicals
  • Smoke
  • Shampoo
  • Ear mites and other parasites


  • Excessive itching or scratching – flea allergies can happen with a single bite
  • Watery or runny eyes or nose
  • Sudden snoring due to inflammation in the back of the throat
  • Sneezing

Diagnosis & Treatment:

  • Skin tests and cultures to rule out bacteria, fungal infections, or parasites
  • Allergen tests to determine the type of allergy
  • Eye stains, ocular exams
  • Eye drops or ointments may be prescribed to decrease inflammation

Conjunctivitis: Yes, cats can get Pink Eye, too.

Conjunctivitis means inflammation of the conjunctiva, which is all the tissue around the eye that is normally pink. In a cat, you shouldn’t really see conjunctiva unless there is a problem with it, and if the conjunctiva is inflamed by foreign bodies, infection, or injury, then the eye will appear red, puffy, and irritated. Your cat may squint. . Some other causes can be Feline Herpesvirus or Calicivirus. Whether the Conjunctivitis is bacterial, viral, or fungi-based, it can be cleared up quickly with a vet visit, diagnosis, and treatment.


  • Whites of eyes are red and possibly swollen
  • Frequent blinking or rubbing the eyes 
  • Squinting
  • Sneezing or coughing
  • Eye discharge that is white, yellow, or green
  • Third eyelid covering part of the eye 

Diagnosis & Treatment: 

  • Ocular tests, including ocular staining to check for corneal ulcers on the surface of the eye, ocular pressure testing to check for glaucoma, ocular exam, and possibly culture to determine the origin of the infection
  • Blood or urine samples to assess overall health 
  • Eye drops or topical ointments applied to the eyes to reduce inflammation and heal the eyes
  • Surgical removal of any foreign bodies debride corneal ulcers or repair a prolapsed third eyelid gland
  • Oral antibiotics or anti-viral medications may be prescribed if an infection is present

Feline Herpesvirus (FHV-1): It’s not just a cold.

Most cats have at one time or another been exposed to Feline Herpesvirus – it is very common. Some cats will show symptoms for the virus, whereas other cats will be carriers and show no symptoms because the virus lies dormant in their systems.

The virus can activate at any time, especially when a cat is stressed. Unfortunately, there’s no cure, but FHV-1 can be managed to make the cat more comfortable and minimize flare-ups.


  • Upper respiratory symptoms – coughing, runny nose, or sneezing
  • Conjunctivitis – swelling or inflammation of the outer lining of the eye
  • Corneal ulcerations – these are serious eye issues that need immediate vet attention to maintain vision in your kitty

Diagnosis & Treatment:

  • Blood and urine samples
  • Fluorescein eye stain test to detect if an ulcer or injury is present
  • Eye drops or a topical ointment to ease symptoms and heal infections
  • Oral antibiotics or antiviral medications to treat an upper respiratory infection if present
  • Lowering stress to prevent reactivation of the virus
  • Lysine vitamin supplements may help reduce or eliminate symptoms associated with virus flares

Blepharitis: There’s a reason for those puffy eyes.

Blepharitis is an inflammation and infection of the eyelids. It can also involve the muscles, connective tissues, and glands of the eye. It’s more common in flat-faced cats like Persians and Himalayans, but other breeds of cats can get it, too. It can be caused by allergic reactions (like a flea bite) tumors, trauma to the eyelid, and other conditions like diabetes. Your cat’s own hair can also cause Blepharitis if it irritates their eyes. In addition, if your cat’s eyelid rolls in or out, that can also cause inflammation. 


  • Swelling of the eyelids
  • Rubbing or scratching at the eyes
  • Dry or crusty areas around the eyes and discharge
  • Hair may come out leaving leathery or bare areas around the eyes

Diagnosis & Treatment:

  • Examination of the eyelids and surrounding areas to determine the presence and extent of inflammation, plus the cause of the infection 
  • Blood or urine tests and possibly cultures or biopsies to detect if an infection is present
  • Clean around the eyes while they’re healing with cotton balls wet with warm water 
  • Apply warm compresses to the area to help soothe the eyes
  • Get an Elizabethan collar (Blepharitis can be very itchy) to protect the eyes during the healing process
  • Topical ointments and eye drops may be prescribed to treat inflammation or infection
  • Oral antibiotics  for bacterial infections, in these cases the underlying cause still needs be addressed for a longer-term solution

Keratoconjunctivitis Sicca: This is also known as Dry Eyes or Keratitis.

Keratoconjunctivitis Sicca…a really intimidating word that simply means dry eyes. It can be a secondary bacterial infection of FVH-1, but can also crop up with Conjunctivitis, allergies, or for genetic reasons. 

Tears have antibacterial properties in them and protect the eyes by flushing irritants and providing lubrication. Having a dry eye condition is very uncomfortable and can cause severe issues if not treated, including blindness. Luckily, it’s relatively easy to provide comfort to your kitty if this is the problem, but dry eyes are usually not curable. You will need to manage the symptoms to keep your feline buddy comfortable.


  • Excessive blinking
  • Swollen, red, crusty eyes
  • Green goop around eyes
  • Your cat may be reluctant to open their eyes
  • Inflammation of the eyelids
  • Light sensitivity
  • A dull coating or dry look to the cornea or outside of the eye


  • Eye examination to determine if dry eye may be the problem
  • A Schirmer tear test to measure  the percentage of moisture in the eye
  • A fluorescein stain test to check for any ulcers or erosion of the cornea
  • Eye drops may be prescribed to stimulate the production of tears, or antibiotics if an infection is present. Eye lubrication may also be prescribed to provide comfort. 

Are your cat’s eyes healthy?

As you can see, there are many reasons a cat can develop an eye infection. Some are not as serious as others, but all can be treated to keep your kitty comfortable. Bacteria, viruses, fungus,  allergies, and anatomical defects can all threaten your cat’s amazing vision talents. So if you look at your beloved kitty and if their eyes are not as clear and beautiful as they usually are, maybe it’s time to see your vet. With the right treatment and insurance to help cover it, your cat can be back to their old self in no time. 

Lynn Guthrie

Writer, Mom of a Fab Fur Fam of Five
Lynn is a writer and long-time Learning & Development Manager at a large PNW retailer. She's also mom to 3 dogs & 2 cats!
Reviewed by Dr. Sarah Wooten, DVM
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