How rare are a di-colored irises on a horse?

Question

As when one eye is dark and the other pale grey.

Answer 1

I dont think that they are too rare. 2 horses at my barn have different colored eyes. One is an appy and the other is a paint. Then there is another paint with 2 blue eyes.

Answer 2

It is really rare

Answer 3

My sister says that usually paint horses have di-colored irises.  She says that a lot of horses have it.

Answer 4

A horse I once rode had one brown eye with specks of blue, and then another just brown one. She was a thoroughbred, not even a Paint. Rare I guess.

Answer 5

Not too rare. Blue eyes usually accompany white markings that extend over or near the eye. So it's not unusual for a horse, especially a paint/pinto horse, to have a wide asymmetrical blaze that only causes one eye to be blue.