Eye colour in cats can vary greatly from shades of yellow and green (golden, amber, hazel, orange, etc) to blue. Generally speaking, it's not the breed but the colour and pattern that affect the eye pigmentation: blue eyes are common in predominantly (solid) white cats and in cats with pointed markings. Thus, the typical blue-eyed breeds are the Siamese, Ragdoll, Birman, Snowshoe, Tonkinese, Balinese, Thai cat (the traditional Siamese), Javanese, Turkish Van, Himalayan and Ojos Azules. This trait, however, can turn up in tabby, black-and-white, tortie, and other cats as well. Blue eyes occur equally often in male and female cats.
Photo by lque Mon
Eye colour and deafnessA lot of people think that pure white cats with blue eyes are deaf. It's not quite so. Predominantly white pigmentation and blue eyes only indicate higher chances of deafness. Blue-eyed white cats are not all deaf. Although it's extremely rare, deafness can also be seen in cats with other eye/coat colours. It all depends on the cat's genotype, i.e. on what genes the cat has inherited. The cat's phenotype (its physical appearance) has nothing to do with it because blue-eyedness and whiteness can be caused by different genes which can or cannot entail deafness. For example, even though the Turkish Van is predominantly white, this breed is not usually associated with deafness like the Van Kedisi and the Turkish Angora.
The following figures have been taken from scientific studies around the world. Pure white cats make up about 5% of the general cat population. 15 to 40% of these pure white cats have one or two blue-eyes. Out of these pure white cats with one or two blue eyes, 60 to 80% are deaf. Only 30 to 40% of pure white odd-eyed cats are deaf.
Predominantly white cats that have one blue and one other-coloured eye ("odd-eyed" cats) may be deaf on the same side as the blue eye. Orange eyes usually indicate the cat is free of hearing problems.
The blue-eye gene in colourpoint cats is not usually associated with deafness.
Blue eyes in kittensAll kittens are born with blue eyes, but the colour will not necessarily remain blue. When a kitten is about one month old, its eyes begin to change colour to any possible shade (iridescent green, golden, amber, yellow-golden, or a new shade of blue). Sometimes, the eyes will remain blue of course. The adult eye colour is most likely to settle when the kitten is about three months of age.
Read also: Breeds of dogs with blue eyes