Cat eye color is important to breeders of purebred cats. The colour is referred to in the breed standards4 and is sometimes linked to coat colour. An example of linkage might be silver tabby cats that are often required to have green eyes3. For instance, the breed standard for the Russian Blue is described as:
“Vivid green. Set rather wide apart, almond in shape, not small and deep set”…1
 | Russian Blue Cat |
“EARS: strikingly large, pointed, wide at base; continuing the lines of the wedge….Eye color: deep vivid blue”
The above applies to the Modern Siamese cat. We know that Siamese cats have blue eyes.
Left: This is not a Modern Siamese but a Traditional Siamese.The eye color is a deep vivid blue in line with the CFA eye color standard for the Modern Siamese cat.
Although, I suspect that the color balance of this photo favours blue! Photo: Juergen Kurlvink
In fact the only eye colour that is naturally linked to coat colour is blue. Blue eyes are caused by “forms of albinism” 3 that results in lack of pigmentation in the iris of the eye and coat. The iris is the part of the eye that we see that produces the colour of the eye. It controls the amount of light that the eye lets in.
Eye colour in cats in more apparent than it is for humans because their eyes are larger in relation to their heads. A cat’s eyes are unusually large. If human eyes were of comparable size in relation to the head, they’d be several inches in diameter, it is said. The cat’s large eyes give them a baby-like appearance.
Apparently green eyes or eyes with shades of green have become common in random bred cats (moggies).
Kittens are often born with blue eyes which change colour when they become adults. This is because eyes without pigment in the iris look blue due to scattered light. When pigmentation develops the eye takes on a color.
There is a wide range of eye colours from copper at one end of the spectrum to blue at the other. There are also odd eyed cats. This condition is caused by the gene that produces coats that are either totally white (dominant white gene) or spotted white (white spotting gene or piebald gene).
Here is a range of cat eye color:
 | Copper |
 | Copper-orange |
 | Orange |
 | Orange |
 | Orange-yellow |
 | Yellow-hazel |
 | Hazel |
 | Green |
 | Aqua-blue |
 | Blue |
 | Blue |
 | Odd-eyed Cat Photo: by sly06 (Flickr) |
***All the photos are thumbnails – please click on them to see large format versions. They are also all (unless stated otherwise) copyright Helmi Flick. Please respect copyright. Thanks
As mentioned, cat eye color is formed in the smooth muscle cells of the iris. The iris creates the pupil, the aperture in the center of the eye that lets the light in to the retina in a controlled manner.It is the amount and intensity of pigmentation that is in the front and rear of the iris that determines cat eye color.
Sectoral heterochromia
Odd-eye color is called complete heterochromia. It is caused by the dominant white gene. A rarer form is sectoral heterochromia when each eye has two colors: blue (or no color) and orange or yellow. Blue is caused by light refraction not pigmentation.
Some other instances where eye color is specified by the breed standard would be:
Nebelung: Color: Green with yellow/green mixture allowed. In kittens, changing from yellow to green. Should show green halo around pupil by 8 months. As vividly green as possible at maturity, which could be at 2 years or more. The more richness and depth of color, the better (TICA breed standard verbatim).
Turkish Van: Color is amber, blue or odd eyed.…Allow for faded eye color and greenish cast to amber eyes in cats over 18 months of age (TICA breed standard verbatim extracts).
There are many more. Start here for articles on all the cat breeds.
There is one last point to make. The true albino cat as opposed to the all-white cat (carrying the dominant white gene) has no pigment in the eye and therefore it looks pink:
Cat eye color – Associated pages:
- Cat Eyes
- Are Cats Color Blind?
- Cat Anatomy
- Cat Eye Colors from VG (Valley Girl)
- White fur – deaf cat
Cat eye color – Notes:
1. russianblue.org.uk – Russian Blue Breeders Association
2.cfainc.org/breeds/standards/siamese.pdf
3. The Encyclopedia Of The Cat by Dr Bruce Fogle
4. Breed standards are the guidelines issued by each cat association as to the requirements regarding the appearance of individual registered breeds.
Hi everyone,
I recently adopted this sweet cat and named her Fenty. She is white persian, and she has an grey (? or aqua blue) eyes mixed with some copper orange in both her eyes. Her pupils are also light up not as black but as orange/reddish color.
Can anybody tell what color her eyes are? Does she really have sectoral heterochromia? I’m just too curious
Thank you – he’s very striking for a regular moggy!
His mum was mainly black with some white as was his brother so Sweep must be a throwback!
He is super handsome. The white spotting gene probably gives him the blue eyes. He has Turkish Van markings by the way. As the original origin, these cats come from the Van region of Turkey.
https://pictures-of-cats.org/cat-coats-the-van-pattern.html
My white and black cat, Sweep, has beautiful blue eyes – his litter mate and brother are both green eyed tuxedo cats
Hi Lilie, thank you for commenting and showing us your cats (beautiful). About the green eye colour, this is normal. My opinion is, and I’m guessing a little bit, that the eye colour will end up yellow/orange and that little bit of green is because there is still some blue in the eye because your cat is young. The blue is due to refraction of light and not the colour of the pigmentation in the iris. Blue + yellow = green.
As I said, it will disappear and I think the eye will settle down to be a yellow/orange type colour.
His sister on the other hand has the most beautiful siamese eyes, here’s a picture