Cat Eye Disease (list)

Cat with both eyes diseased
Cat with both eyes diseased. Bulging eye, glaucoma?
Two useful tags. Click either to see the articles: Toxic to cats | Dangers to cats


Feline eye disease – Here’s a long and comprehensive list. The first thing to do is to define the phrase “disease” in the search term (another search term is “cat health eye” by the way). It is easy to acquire a misconception with regard to terminology. The word “disease” can be used in a very wide sense. Essentially it means an abnormal condition that exists in an organism (meaning in this instance, a cat) that affects in a negative manner the normal working of the body. The negative impact can mean the death of the organism.

cat eye
Cat eye photo by nicora – healthy eye

Sometimes we limit the term “disease” to mean infectious diseases (or at least I do). An infectious disease is one in which the normal working of the body is affected negatively by the presence of a pathogenic microbial agent, which is a very small object that causes disease. A well known example would be a virus. An individual viral particle is a minute object (sub-microscopic) that consists of DNA or RNA (genetic material) coated by a protein shell and which has to “live” inside a cell of the host, where it reproduces. Its presence kills the cell. When this happens a lot the host organism (in this case the cat) suffers with symptoms of illness.

Cat’s eyes are a very important sense for the cat and they are adapted to stalking and hunting particularly at dawn and dusk (crepuscular activity). They are large. If our eyes were the same size as a cats in proportion to our body they would be 8 inches across (src: Cat Owner’s Home Veterinary Handbook by Drs Carlson and Giffin). They have two readily apparent differences to ours (a) a mirror like layer of cells behind the retina at the rear of eye, which reflects light back to enhance the image in dark conditions and (b) an extra eyelid that can be seen sometimes and which serves to protect the eye when walking through brush and tall grass, for example, and to keep the eye clean. Feline eye disease therefore has a major impact on their lives. A cat sees slightly differently to people – see a comparison.

Note: A number of these diseases and conditions are painful to very painful (scratched cornea for example) and therefore a cat owner should seek prompt veterinary care.

Returning to feline eye disease in the widest sense; here is a highly summarized list. It is is meant to provide pointers for non-qualified people, no more:

Bulging left eye on cat
Bulging right eye on cat. A vet said it might be caused by (a) congenital defect (b) trauma – injury (c) cancer or (d) infection.

1. The eyes bulges from the eye socket (bulging eye) – several possible causes include (a) a blow to the eye fracturing the bones around the eye resulting in a build up of blood/fluid behind the eye forcing the eye forwards, (b) sinus infections spreading to the eye (c) a growth, malignant or not, behind the eyeball forcing it outwards and (d) “hard eye” – glaucoma (see below). But also see caption to image above.

Update: another example of feline glaucoma:

cat glaucoma
Cat Glaucoma

2.The eye sinks into the eye socket (sunken eye) – causes (a) dehydration and rapid weight loss (b) eye retractor muscle in spasm, which can be due to a tetanus infection or corneal injury (c) damage to nerve in the neck of the cat due to a neck injury for example (d) severe injury.

3.  Jerky eye movements – indicates a problem with the inner ear.

cross eyed cat
A much loved cross eyed cat called Tully – photo by johnnyalive

4. Cross eye – Siamese cats commonly suffer from this feline eye disease and it is an inherited (genetic) condition. Other causes are (a) muscle paralysis (b) brain tumor (c) nerve injury. The classic Siamese cat squint does not affect bipolar eyesight. Inherited reason why Siamese are cross-eyed.

5. Inflammation of the eyelids – caused by (a) fighting leading to an infection, which in turn leads to scratching and more damage (b) mange mites (c) ringworm infection.

6. Foreign bodies – seeds or wheat (during harvesting) are one example. Causes discomfort and watering.

7. Sudden swelling – a feline eye disease caused by an allergic reaction from insect bites, allergens in food and/or drugs.

damaged cat eye car accident
Eye lost in car accident

Photo above – I’m glad he made it. Cars are horrible for cats. Cat enclosures can be an answer or cat strollers! – photo by Fahara

8. Eye lash irritation – Eyelashes although rare for cats can turn inwards causing irritation.

9. Rolled in eyelid – (a) can be inherited in Persian cats and (b) in any cat due to conjunctivitis or a lacerated eyelid. Also thought to be a disease affecting the Bengal cat. Called Entropion. Very uncomfortable. Affects people as well.

10. Rolled out lower eyelid exposing eye to irritants – the feline eye disease is caused by (a) birth defect (b) badly healed cut of the lower lid.

11. Cancer of the eyelid

Nictitating membrane in Cat
Nictitating membrane in Cat. Photo: Wikimedia Commons

12. Film over the eye – this is an opaque third eyelid becoming visible (it is called the nictitating membrane, “haw” or in latin: palpebra tertia). Caused by (a) ill health generally (b) injury (c) combined with bulging eye – see above (d) combined with sunken eye – see above (e) Key-Gaskell Syndrome (f) Horner’s Syndrome (g) Haw Syndrome. The haw is designed to protect the eye. Associated page: what can the third eyelid tell us?

Cat Watery Eye
Cat Watery Eye. Cause: unsure. Possibly trapped piece of grass in nose. Tried to remove it without success. Hopeful it will dissolve. It may be cancer of the nose. We are waiting and watching. Update: cause: cancer behind or near the eye. He passed away a few months later. He name was Charlie. My cat. RIP.

13. Watery eye – tear stain overflow – tears running down the face – cause (a) eye is irritated and watering too much (b) feline viral respiratory infection (c) poor tear drainage due to blockage or over breeding (Ultra Persians and Ultra Himalayans suffer from this due to the flat face) (c) infection of the duct drainage system (d) injury (e) cancer. My cat suffers from this and his vet says it might be due a foreign body trapped in the nose or perhaps at he back of the mouth. We are not sure. It may be cancer of the nose.

Picture of cat with pink eye before and after
Picture of cat with pink eye before and after

14. Red eye (pink eye) – conjunctivitis – common feline eye disease – it is an inflammation of the membrane covering the back of the eyelids and the surface of the eyeball up to the edge of the cornea (front of the eye). 3 types: (a) Serous Conjunctivitis – mild condition – causes (i) early sign of feline viral respiratory disease (ii) allergens, irritants (b) Purulent Conjunctivitis – “purulent” means discharge from the eye contains pus – cause (a) secondary bacterial infection (b) virus if both eyes are affected (c) Clamydia – one eye first (d) Mycoplasma – one eye first (e) fungal infection – rare (iii) Follicular Conjunctivitis – mucous glands near the eye become rough which irritates the eye – cause (a) pollens (b) allergens (c) infections. See more.

Cat eye worm(s). This appears to be eye worms with severe pink eye.
Cat eye worm(s). This appears to be eye worms with severe pink eye.

15. Eye Worms – these are worms transmitted by flies that eat eye secretions. They are relatively large and can be physically removed by the veterinarian.

Cloudy cat eye
Cloudy cat eye

16. Cloudy eye – is what it says – loss of transparency. Can be localized or all over the eye – causes (a) keratitis – see below (b) glaucoma (c) cataracts. Requires urgent vet attention.

17. Corneal abrasion – loss of transparency – the cornea is the front, clear, part of the eye – caused by (a) injury resulting in a scratch (b) eye lash irritation if high up on cornea – 8 above (c) embedded foreign body – lower part of cornea. See Cat Eye Scratch.

18. Corneal Ulcers – loss of transparency – cause (a) injury to cornea (b) infection from virus, bacteria and/or fungus (c) diet. Urgent treatment is important is required to avoid this feline eye disease causing greater damage.

19. Keratitis – inflammation of the cornea – eye discharge, squinting, rubbing and protrusion of 3rd eyelid. The difference to Conjunctivitis is that eye discharge is not chronic and this is painful. This condition causes loss of transparency of the cornea. Two types (i) Ulcerative Keratitis – cause (a) injury causing abrasion or ulcer, which becomes secondarily infected (b) feline herpes virus and (ii) Chronic Degenerative Keratitis – unique to cats particularly Persians, Siamese and shorthair cats – inflamed tissue forms a black blob of opaque cornea -this feline eye disease has an unknown cause.

Lion with cataract in his right eye
Lion with cataract in his right eye. Photo: Fr Lawrence Lew, O.P.

20. Cataracts – opacity of the lens of the eye. It might be a spot. Rare in cats cause (a) injury (b) infections (c) inherited (d) diabetic cats. Cats can usually get around alright unless severe. Read more if you’d like to

Cat with glaucoma in his right eye
Cat with glaucoma in his right eye

21. Glaucoma – hard eye – caused by increase in fluid in the eye. Symptoms: tears, squinting, redness. If fluid pressure in the eye increases to more than 30-50 mmHg the eye becomes significantly larger. If left untreated the retina will be damaged and the lens become misaligned. Can occur quickly or slowly (weeks). Urgent action needed (vet).

22. Soft eye – inflammation of the inner pigmented area of the eye – this is a painful feline eye disease- squinting, watering – cause (a) infection (b) injury – penetrating (c) larvae of worms.

Cat with retinal damage due to hypertension
Cat with retinal damage due to hypertension

23. Retinal disease – the retina is the light sensitive cells at the back of the eye that capture the image and transmit it to the brain via the optic nerve. Eye loses ability to interpret the light received -causes (a) genetically linked PRA in Persians, Abyssinians and Bengals (b) inflammation from infection (c) hypertension (d) injury (e) dietary deficiency of Taurine affecting the center of the retina.

Feline eye disease – Primary Source: Cat Owner’s Home Veterinary Handbook by Drs Carlson and Giffin. This is a fine book, very comprehensive and I apologize if my tight summary is not up to scratch.

Feline eye disease photos: are either published under a creative commons license = Attribution-NonCommercial-NoDerivs License or are judged to be in the public domain. If that is incorrect please leave a comment.

Please search using the search box at the top of the site. You are bound to find what you are looking for.

Useful tag. Click to see the articles: Cat behavior

25 thoughts on “Cat Eye Disease (list)”

  1. Hi there, would anyone be able to tell me what is going on with my 7 years old cat’s eye?? I’m very worried and I can’t get into a vet for the next week.

  2. Chandler Watson

    Hey! My 17 year old buddy here has had some issues with his eyes lately. It seems as if the pupils are always dilated completely. As well as the eyes look sortve sunken into the face. I cant afford a vet right this moment so I’m hoping for some ideas on alleviating any sort of pain he may be having, until I can see a professional

    1. Chandler, please tell me what diet you are feeding your cat? I think this is an indication of gradual blindness due to progressive retinal atrophy bearing in mind his age. It may also be retinitis – a degeneration of the ligh receptors of the retina. But please tell me his diet before I provide some more information.

      I am not a veterinarian.

    1. This looks like a bacterial infection in a bad wound to me. It is hard to from the picture where it is. But it is bad and it has been there for a while. This is very urgent. She is in pain. Please do something. Get help.


      1. Susan Colantuono

        If you can afford veterinary care , than why in God’s name haven’t you taken this poor animal in with such an obviously severe infected wound that without question is extremely painful .

  3. I’m worried about my Bengals eye. What started out as a freckle has now grown to cover and distort the eye.. please see pictures. This is the only thing wrong and it does not appear to bother her at all.

    1. Hi Roxanne. I am not a vet but I’ll have a go at this. I think the freckle is something different to the other area which looks like it could be a cataract. Bengal cats have a predisposition to cataracts and retinal atrophy (PRA). That’s my best guess. I’d definitely have her checked out by a vet. It may not bother her because her right eye is good and cats compensate so well. I suspect her vision is slightly impaired. Good luck.

  4. So one of my kittens had suffered an eye infection when born and since recovering from it, has had one cloudy eye. Nothing else seens to be wrong besides the cloudiness.

      1. Was there anything further about this particular cats’ eye condition? I recently started caring for a community cat whose eye (I’m told) was infected as a kitten and the eyeball blackened and stayed that way. I couldn’t get any more info on it nor can I find anything similar online. I also have another street cat who has an eye weirdness I can’t find anything on, so if anyone has some good online references to rare feline eye problems I’d appreciate it. Thanks.

  5. My mother’s cat has a clear membrane across her eye, the pupil is cloudy and it seems that both her eyes are slightly larger than they should be. Her third eyelid is always visible. We have been using eye drops that flush debris from the eye, but it doesn’t seem to be working. I am worried she may be going blind and fear for her. Is it something serious? If so, does she need immediate attention? It is always expensive so I’m afraid she may not get the treatment she needs. I have cried dozens of times about it, feeling it is my fault. Her name is Luna and I raised her from birth as well as her two sisters and her brother.

    1. Hi there. It is certainly serious enough to see a vet immediately about it. At least get it checked out and take it from there. A check up would not be that expensive. You have to find out what is wrong. If the dagnosis is not good and the treatment expensive, you might try online crowd funding. It can work very successfully. Your story is very personal and tender. It may attract attention and donations. But no guarantees of course. It is certainly not your fault. Good luck to you both.

  6. i am adopting a little shelter cat, with
    near blindness. they vet who made this diagnosos is not 1 i trust. she is 1yr.
    is it possible,with proper feeding she might recover? i am also concerned as my male cat is a expensive ragmuffin.
    will this infect him. i looked at this girl, there is no sign of infection,only a cloudy membrane. she
    does see but is unable to see thing close up.

  7. I have several cats that have inflamed capillaries going around the the iris. They are of a reddish brown color. They also have smaller red veins in the iris. I had an opthamologist look at two of them and he said one had herpes of the eye and the other had melanosis. They both have the same discolorations though.

  8. I have a kitten with a badly bulging eye due to sinus infection ipossible to get to a vet have been using generic powdered anti biotic and crystal vitamin c obtained specifically for felines.. No improvement.. someone said it IS curable.. Please TELL How?… Please Thank You

    1. If it is certain that there is a bacterial infection in the sinuses you should use a more precise antibiotic. This may mean testing for the bacteria and tailoring the antibiotic to it. Why are you sure the cause is a sinus infection? Have you diagnosed the cause with some certainty? I wish you and your cat the very best. I’d bite the bullet (and I know how expensive vets are as I’ve recently spent $1,500 on my cat) and get a good vet to help you. Some vets are better than others.

      An operation is available to flush out sinuses. That would at least eliminate the cause of the pressure. I think this needs urgent attention but I understand how you feel I really do.

  9. that was a very good article, but I didn’t see what my cats eye has,
    Looks like eye liner, on the bottom of the eye, not totally across, has a little then breaks and continues on , two short black lines. Does anyone perhaps know what this could be.

    1. Hi Debbie. Eye-liner on the bottom of the eye sounds like pigmentation in the skin rather than a disease. I presume your cat is healthy or behaves in a way that tells you he/she is healthy. Can you upload a photograph? Just below the comment box is the button to upload a photo. A photo would help.

      Thanks for visiting and asking.

  10. I’ve seen quite a few eye losses in cats that seemed to be due to an URI.
    In actuality, most were caused by a herpes viral infection.
    Not curable but can be arrested with treatment.

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