Coloboma of the iris is a hole or defect of the iris of the eye. Most colobomas are present since birth (congenital).
Coloboma of the iris may look like a black, round hole located in or next to the colored part of the eye (iris). It can look like a black notch of different depths at the edge of the pupil. This gives the pupil an irregular shape. It can also appear as a split in the iris from the pupil to the edge of the iris. (from nlm.nih.gov (link))
A small coloboma (especially if it is not attached to the pupil) may allow a second image to focus on the back of the eye, causing:
- Blurred vision
- Decreased visual acuity
- Ghost image