If your heterochromia is hereditary, I am sorry to tell you that there is almost nothing you can do about it, for there is no permanent cure for it. However, there are medications that can treat heterochromia, such as Lumigan (or Latisse). They can turn the light colored iris dark because of their certain side effect. The heterochromia is not a big issue. If it really bothers you, colored contact lenses can help you look better. Sometimes, heterochromia can be one symptom of other eye diseases like pigmentary glaucoma. So when a change in eye color suddenly occurs to you, you should have your eyes thoroughly examined.