Iris Heterochromia is the difference in the coloration between both iris. It is either hyochromia in which the affected iris is lighter in color than the normal one or hyperchromia in which the affected iris is darker in color than the normal one. There are many causes of this condition and these causes can be divided into congenital and acquired.
Causes
Congenital causes
1- Hypochromia.
Congenital Horner syndrome, Waardenburg syndrome and facial hemiatrophy.