This study will identify the genes responsible for uveal coloboma, an abnormal development of the eye caused by incomplete closure of a normally-occurring gap in the eye (the optic fissure) after the fifth week of life in a human embryo. There have been studies of families in which more than one person has been affected by this disorder. Coloboma occurs in about 1 of 10,000 live births and may cause significant vision loss. Researchers seek a better understanding of the genes responsible for this disorder.