Why does my cat have a black ring and uneven pupil dilation?

It looks like Memo could have changes to the iris due to anterior uveitis or inflammation in the eye. This can cause the pupil to become smaller and the iris to change colors. It’s also possible that Memo has a growth on this eye. I would recommend seeing your veterinarian so they can examine Memo’s eye in person. They may want to check his eye pressure.

There are a couple of possibilities here for the changes to Creo's iris. One is iris atrophy, which is a normal aging change. This can often result in pigment change and a "moth-eaten" appearance to the iris or an irregular iris border. Another would be a uveal cyst, which is a darkly pigmented circular lesion that can be attached to the iris. Both of these are generally benign. If you notice any changes in Creo's vision, changes to the eye, or signs of pain (squinting, redness, swelling, etc.), have him re-evaluated by your vet just to be safe.

Hello, I agree that Buddy's left pupil appears more dilated than the right. This could be associated with age related atrophy of the iris (makes up the pupil). However, cats can get cancer of their eye and this it would be best to have him evaluated to ensure there is not mass growing behind the pupil and to rule out other potential abnormalities within his eye. Hope this helps and best of luck.

Thank you for submitting your question regarding Emma. I would recommend that she has her eye evaluated by her veterinarian. Hopefully it is just a normal pigment change, but cats can develop a type of cancer known as melanoma in the eye. You would want this diagnosed as soon as possible. I hope this information helps you and Emma!

It could be iris melanoma but there is no way to know just by looking at a photo. You should have a veterinary ophthalmologist check the eye if you are really worried. At Cali's age I highly doubt it is melanoma but it is possible.

There is anisocoria (the two pupils are unequal in size) and possibly ptosis of the upper eyelid (the eyelid cannot open normally) on the left side (where the pupil is bigger). There are many causes that can provoke this presentation: -Corneal injury such as an ulcer. -Disease or injury to the brain or to the nerves running to the affected eye, such as Horner’s syndrome. -Glaucoma, a disease in which there is increased pressure within the eye (the pupil in the affected eye will be dilated). -Uveitis, or inflammation of the interior of the eye (the pupil in the affected eye will usually be constricted). -Retinal disease. -Scar tissue formation between the iris and the lens (called posterior synechia), a condition that may develop following uveitis. -Iris atrophy (a decrease in the amount of tissue within the iris) usually a degenerative change associated with aging. -Congenital defect of the iris, in which the iris tissue does not develop properly. -Cancer within the affected eye. -Spastic pupil syndrome - a syndrome that may be associated with feline leukemia virus infection. -Other infectious diseases such as feline immunodeficiency virus or toxoplasmosis. Unfortunately is difficult to be more specific than that and a clinical examination at your local veterinarian is essential to confirm these clinical suspicions and treat appropriately. Antibiotics may be needed. Hope this answer was helpful, but please do not hesitate to contact us again on the forum or by requesting a consultation if you have any more questions or to discuss it any further. If this answer was helpful please let us know, this will be used to improve our service!

It is not uncommon for cats to develop brown or black spots on the iris. A pigmented area on the iris can be benign or malignant, and differentiating them is sometimes difficult. My guess is that these spots are what we call iris nevus. These are benign (like freckles). Since she has so many, this would be called iris melanosis. Iris melanosis is classified as benign, but in time, it may progress to a malignant melanoma. Although melanomas are rare in cats, the eye is the most common site for it to show up. The first hint that this could be melanoma is rapid growth. If you know the spot(s) is getting larger quickly, that is a warning sign. If the shape of the pupil has become deformed as it dilates and constricts, that is another potential red flag. I suggest you have Dixie examined by your vet to get a diagnosis. She needs a thorough exam with a ophthalmoscope. Hope this helps. Best wishes.