White cat with one amber and one blue eye

Heterochromia, where a cat has odd-eyes, most commonly occurs in cats with white fur.

© Natali Kuzina - Shutterstock

Is it normal that my cat's eye colour changes?

By Greta Inglis Dog Behaviourist | Animal Behaviourist

Published on the

The eyes are the window to the soul, but they can also tell us about our pet's health. Here we take a look at what a change in eye colour can mean for your cat.

Between the ages of 3-8 weeks a kitten's eyes may change, based on on how much melanin there is in the iris. The darker the pigment, the darker the eye colour will be.

How will I know if my adult cat will have blue eyes? 

It's the production of melanin that determines whether or not your cat will have blue, yellow, copper or green eyes. By the time your kitten reaches 3 months of age, you will know exactly what the colour of your adult cat's eyes will be

What does a sudden change in cat eye colour mean? 

While most cats will have two eyes of the same colour, odd eyed cats are not uncommon. Known as heterochromia, this striking appearance is most commonly seen in cats who possess the white spotting gene responsible for white patches, bibs and socks. 

If your cat's eye has changed colour suddenly, this may indicate a health issue that needs looking into. 

Want paw prints in your email?
Let's do it!

9 health problems associated with a change in the colour of a cat's eye

If your cat's eye has changed colour, you may be wondering if an underlying health condition is responsible. Here we take a look at 9 reasons a cat's eye can change colour.


Uveitis is caused by an inflammation of the uveal tract of the eye, which can result in the protrusion of your cat's third eyelid. This can be a symptom of diabetes, high blood pressure, or a bacterial infection.

Uveitis can cause your cat's eyes to look red or cloudy, and the condition will need veterinary treatment. 

Portosystemic liver shunt

While copper coloured eyes can be natural, they may also indicate your cat is suffering from a portosystemic liver shunt. This is a blood vessel anomaly, that results in blood from the abdominal organs being diverted to the heart. In bypassing the liver, toxins can't be cleared from circulation. 


Jaundice, caused by obstructed bile ducts, not only causes discoloration of the skin. It can also lead to discolouration of the eyes, which may lead to your cat's pupil looking yellow in colour. 

Bacterial infections

Feline viral rhinotracheitis and feline calicivirus are fairly common among our feline friends. If your cat has a cold, their eyes may become red from irritation and rubbing.

Corneal ulcers

Corneal ulcers are most commonly caused by blunt trauma, through an accident or a cat fight. Recurrent feline viral rhinotracheitis can also lead to ulcers, which may result in a milky eye colour or a redness to the eye. 


Perhaps one of the more common complaints to the eye, conjunctivitis is caused by an inflammation of the thin mucous membrane. Symptoms include a watery green or yellow discharge, which may need to be treated with antibiotics.


Caused by increased pressure in the eye, glaucoma that's left untreated can cause loss of sightA key symptom to look out for is a cloudy white, milky eye. If your cat's eye has changed colour in this way, it's worth booking a visit with your vet to rule out glaucoma. 


Entropian is an abnormal rolling in of the upper or lower eyelids. Irritation can cause scratching and redness to the cornea, as there will be painful irritation to the surface of the eye

Eosinophilic Keratitis

This is a chronic inflammatory condition resulting from a type of white blood cell invading the cornea. This can result in the surface of the eye having a pink, white or grey appearance. Long-term, anti-inflammatory medication will most likely be required. 

Do cats' eyes change colour with mood? 

While this may be a commonly held belief, it's unlikely that your cat's eye has changed colour because of their mood. In reality, it's more likely that their eye has changed colour because the tissue behind the cat's retina reflects light in a way that makes the pupil glow. In cats with yellow eyes, this will usually look green, and in blue-eyed cats it will usually look red. 

Do cats' eyes change colour when they die?

If you've experienced the sad death of a beloved pet, you may have wondered what happens to their eye colour when they die. While it may seem as if the eye changes colour, in reality this isn't the case. After death, your cat's eye will become cloudy in appearance, gradually turning opaque over time. 

While a kitten's eyes will change colour as they grow, a sudden change in the eye colour of an adult cat may indicate underlying health conditionsIt's always worth speaking to your vet if you're concerned, to keep your cat as happy and healthy as can be. 

You may also like

More advice on...

What did you think of this advice article?

Thanks for your feedback !

Thanks for your feedback !

0 people found this advice article helpful.

Frequently asked questions

Why did one of my cat's eyes turn brown?

Why did my cat's eye turn yellow?

Leave a comment
Connect to comment
Want to share this article?