Why do cats have 2 eye colors?
These curious cats are suffering from a rare condition called ocular dyschromia, which literally means the irises are two different colors.
Simply put, a cat’s eyes have two different colors, most commonly blue and green, sometimes there will also be cats with yellow and brown eyes.
There are two other types of heterochromia found in cats, the first type is complete heterochromia, meaning the two eyes are completely different colors, the second type is partial heterochromia, meaning one eye Cat’s will have two alternating colors.
This genetic condition, as unusual as it sounds, is surprisingly common in cats.
The reason why cats have 2 eye colors
This condition is often seen in cats with white fur, or cats with a little white hair on their bodies, such as Tuxedo cats and bicolor cats. This heterochromia condition, which is rare in dark-haired cats, is extremely rare in black cats.
The gene that causes cats to have white fur is the same gene that causes two eye colors in cats. It all starts in kittens’ infancy – they’re all born with blue eyes, and you won’t be able to see their true eye color until they’re about 7 to 12 weeks old.
During this stage, pigments – called melanin – begin to change, and the cat’s true eye color will emerge. When a cat grows up and still has the blue eyes of its childhood, it means there is no melanin present.
This is the stage where things get complicated. The gene that produces white fur prevents the melanin pigment from reaching one of the cat’s eyes, while they are in development.
Because of this obstruction, melanin can only travel to one eye, resulting in cats having two different eye colors. In cats with localized heterochromia, the melanin cannot reach one eye completely, and so one eye will be two colors.
If you use flash to photograph a cat with heterochromia, you may see that their blue eye has a reddish tint.
Whereas in a normal cat, both eyes will have tapetum lucidum tissue, which is a layer of reflective tissue. As for cats with heterochromia, the melanin in blue eyes will eliminate some of the color of the light reflected back, resulting in the cat’s eyes being slightly red.