A coloboma is a defect in the iris of the eye. It can appear as a black notch of varying depth at the edge of the pupil, giving the pupil an irregular shape. Coloboma is a congenital iris defect. Sometimes eye surgery or trauma can cause a defect that looks like a coloboma.
Review Date 11/15/2019
Updated by: Franklin W. Lusby, MD, ophthalmologist, Lusby Vision Institute, La Jolla, CA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. Editorial update 05/14/20.