Odd-eyed cats

Photograph of odd-eyed white cat copyright sophiasue105

What causes odd-eyed cats? The color of eyes of an odd eyed cat are blue plus either yellow, orange or green.

The difference in color is due to a lack of pigmentation in the blue eyes. This lack of pigmentation is due to the same gene that causes a lack of pigmentation in the fur.

There are 2 different genes that do this. There is the dominant white gene "W" (meaning the gene is dominant, which in turn means at least half the offspring will have the phenotype - appearance - directed by the gene), and the semi-dominant white spotting gene "S" which has what is called variable expression.


White cat odd-eyed photo copyright dashananda. The cat is big, he snores and he is called Murchik.

The dominant white gene produces a completely white cat masking all other color, while the white spotting gene as the name suggests produces a wide range of coat types from small areas of white (e.g. Tuxedo cat) to larger areas (e.g. Japanese Bobtail) to complete white.

The dominant gene produces cats with both blue or odd-eyed cats as described. It can also cause deafness in the cat. White cats produces by the "W" gene and with 2 blue eyes have a higher likelihood of being deaf than those with 2 orange eyes.

With respect to the white spotting gene, this prevents color pigmentation reaching areas of the body farthest from the spine during development. This can be the paws for example. It might be one eye, in which case the eye will be blue. If the other eye is unaffected it will be a different color.

60-70% of odd-eyed cats that are white can hear (Wikipedia). Quite a substantial percentage are therefore deaf. The deafness is caused by the white gene degenerating the cochlea in the ear starting soon after birth.

The cochlea is a hollowed bone in the inner ear that converts sound to nerve transmissions through the air pressure moving a fluid in the cochlea, which in turn moves minute hairs.

In the Thai Cat Palace (an old Thai syle house on Boromarajajonani Road) odd-eyed Siamese cats are apparently breed, the pure white Maeo Khao Mani. They refer to the eyes as "diamond Eyes". Cats with odd-eyes are favored by the Thai royalty (the same attitude can be found in Turkey in respect of the all white Turkish Angora Cat).

From Odd-eyed cats to Different Cat Breeds