Long list. Any part of the eye can develop with problems or improperly. The list is long and includes abnormalities of the lids, tear drainage, cornea, lens and retina. Some are cosmetic, some functional and some very serious. If you suspect a problem in your child, you should see a pediatric ophthalmologist for evaluation.
Very many. A coloboma of the iris or the retina refers to incomplete fusion. The worst is anophthalmia--uni-or bilateral lack of development of the eye. The sensors in the retina which detect color may be missing. The cornea may be misshapen. The sclera (white) of the eye may be so thin that it appears blue. The iris may be malformed, partially or totally (aniridia). Anomalies of the lens, optic nerve, +.