How rarr is having different colored eyes?

Heterochromia. Having two different colored eyes is called heterochromia iridium. Eye color is determined by a combination inherited genes which determine the amount of melanin in the eye. Heterochromia occurs when a person has different amounts of melanin in each of their irises. It is usually not clinically significant but can be caused by trauma, meds or other syndromes & new onset or infants need dr eval.