Is there any medical use for colored contact lenses?

There are medical indications for using colored contact lenses. There's what's called an iris coloboma, which is a birth defect, essentially, where the bottom portion of the iris does not close completely. The pupil has more of a keyhole type of appearance rather than a circular type of appearance and can be noticeable. This can also give some light sensitivity to people and also, cosmetically, it may make them feel a little bit insecure. Colored contact lenses can be used to match the person's eye as best as possible and fill in that small little defect at the bottom, giving a much more normal appearance of the pupil and the iris.

Another reason a person may wear colored contact lenses is atrophy in the iris. A person may get symptomatic from light passing through the area where there are small little holes, and this way some of the pigment from the colored contact lens actually blocks that light.