Eye And Coat Colors In Cats

Cats' eye and coat colours are determined by their genes. While certain eye colours are associated with specific breeds, others are seen in a wide range of purebred and mixed-breed cats. The two basic colours in cats are red and non-red, with the dominant genes being expressed in priority to the recessive genes.

The colour of a cat's eyes is influenced by two primary factors: iris pigmentation and blue refraction. The iris is divided into two layers, each of which contains pigment-producing cells (melanocytes). The size, spacing, and density of the fibres in the stroma influence how light is reflected and refracted, resulting in the shade of blue. The more melanin in the cat's iris, the darker the eyes will be, and the colours can range from lemon yellow to hazel to deep orange or brown.

The colour of a cat's coat is also influenced by its genes. The two basic colours in cats are black and red, caused by the gene for black (B/b/b1) or the gene for red (O/o). Other colours such as chocolate and cinnamon occur when cats have recessive versions of the black or red gene. The black and red genes can also be influenced by other genes, causing diluted colours such as silver, grey, blue, cream, and fawn.

Yellow, Amber, and Brown Eyes

Yellow eyes can range from a pale lemon yellow to golden shades, merging into a deep and rich amber. Cat breeds with yellow eyes include the Bengal, American Shorthair, Manx, British Shorthair, LaPerm, Bombay, Sphynx, and the Norwegian Forest Cat. The Burmese cat breed is known for its brilliant golden eyes, with show cats often exhibiting the most striking colourations.

Amber eyes are common and have reddish undertones. They are found in the same breeds that typically have yellow eyes, such as the Bengal, British Shorthair, and Manx.

Brown eyes are slightly less common than yellow and amber eyes, and there are no cat breeds known to have true brown eyes. However, brown eyes can appear in mixed-breed cats and are considered a variation of hazel, which can look brown to the untrained eye due to its darkness.

The colour of a cat's eyes is influenced by genetics and the amount of melanin present, just like the colour of its coat. However, there is no proven correlation between a cat's fur colour and its eye colour.

Green Eyes

Cats with green eyes have a little bit of melanin in their irises. The green of a cat's eyes can vary from a green with yellow undertones to a true green and a green mixed in with shades of blue. It's also possible to see flecks of gold or yellow within the iris of a green-eyed cat.

Green-eyed cats can have coats of any colour. Unlike in humans, the amount of melanin in the eyes and the coat is not connected in cats. This means that a cat with a dark black coat with a lot of melanin could still have green eyes with only a little melanin in the iris.

Black cats with green eyes are particularly striking and are a popular subject for photographers.

Blue Eyes

Blue-eyed cats are caused by a lack of pigmentation, or melanin, in the eyes. Melanocytes are cells that produce melanin, and the more melanin produced and the more active these cells are, the darker the eyes will be. Cats with blue eyes have no melanin in their irises. This lack of pigmentation is called albinism, and it is a recessive gene.

All kittens are born with blue eyes because they are yet to develop eye pigmentation. At around six weeks old, the production of melanin kicks in, and the eye colour will start to change to the cat's permanent eye colour. However, some cats will retain blue eyes as their permanent colour.

Some cat breeds that commonly have blue eyes include:

• Siamese
• Ragdoll
• Balinese
• Birman
• Himalayan
• Javanese
• Snowshoe
• Tonkinese
• Turkish Angora
• Ojos Azules

Orange and Copper Eyes

Orange and copper are two distinct eye colours in cats, with some subtle differences. Orange eyes are one of the rarest eye colours in cats, usually appearing in shades of apricot, carrot orange, or marigold. On the other hand, copper eyes are considered the darkest eye colour found in cats, with a deep orange or orangish-brown hue and no undertones of green.

Orange Eyes

Originally developed by British breeders, orange eyes were designed to stand out against any coat colour. The only breed known to regularly showcase orange eyes is the Turkish Van. However, other breeds that may sport this eye colour include the Japanese Bobtail, Maine Coon, Devon Rex, and American Wirehair. If an adult cat's eye colour suddenly changes to orange, it may indicate an underlying health issue, so a veterinary visit is recommended.

Copper Eyes

Copper-eyed cats are quite rare and can be challenging to differentiate from orange and amber eyes. Copper eyes appear as a deep orange with hints of light brown and are devoid of green undertones. Breeds that may exhibit copper eyes include the Japanese Bobtail, Maine Coon, Persian, Cornish Rex, and Chartreux. Similar to orange eyes, the sudden development of copper eyes in an adult cat warrants a veterinary check-up as it could signify a serious medical condition.

Melanin and Eye Colour

The colour of a cat's eyes is influenced by the amount of melanin produced by melanocytes in the iris. The more melanin present, the darker the eyes will be. Copper eyes, being the darkest, have the highest concentration of melanin. Kittens are born with blue eyes due to the lack of melanin, and their permanent eye colour typically develops by 3-4 months of age.

Eye Colour and Albinism

Albinism is a rare genetic condition in cats, resulting from a complete lack of pigmentation. It occurs when there is a mutation of the genes that control pigmentation. Melanin is the pigment that gives colour to the skin, coat, and eyes. It also aids in depth perception and assists the body in fighting off infection and disease.

To be born a true albino cat, both parents must carry the genetic marker for albinism. The eyes of a true albino cat are limited to a very pale blue, or they may appear pinkish or pinkish-blue. This is due to the excess of light reflecting back from the blood vessels within the eye. The skin of an albino cat, particularly the nose and inner ears, may appear pink to pale pink, which is also caused by light reflecting off blood flow.

Although deafness is not a specific sign of albinism, there is a link between cats with white coats and deafness. As albinism is associated with other health problems, the chances of deafness increase in albino cats. However, not all albino cats are deaf.

Partial albinism is much more common than true albinism and is seen in certain members of the "Oriental" family of cats, including the Siamese, Burmese, and Tonkinese. These cats have a distinctive "pointed" coloration that comes from a kind of partial albino genetic heritage. Their colouration depends on heat, with pigmentation developing in cooler areas while warmer areas remain lighter in comparison.

Eye Colour

The colour of a cat's eyes is influenced by several genes, and even littermates of the same parents can have different eye colours. The colour of a cat's eyes is determined by blue refraction, iris pigmentation, and breeding. The more melanin in the iris, the darker the eyes will be. The colour blue in a cat's eyes is the absence of melanin in the iris, which is caused by light reflecting from the eye.

Kittens are born with blue eyes, which may start to change at around six weeks of age as the iris colour develops. By three to four months of age, a kitten will have its permanent eye colour. Any colour change after this age may be a sign of a medical problem.

The most common cat eye colour is yellow/amber, followed by green, blue, and copper. Some cats have two different eye colours, a condition called heterochromia iridium. This is more common in white cats, as it is linked to the W white gene.

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