Unilateral ocular duplication

A rare developmental defect during embryogenesis characterized by unilateral duplication of an eye which may appear as a synophthalmic eye in a single orbit or as two separate unilateral eyes, each in a separate orbit. The malformation is always associated with other anomalies of the central nervous system (such as porencephaly, meningocele, or arachnoidal cysts) and with craniofacial abnormalities. A proboscis is often found. Clinically, moderate mental retardation and epilepsy are typical.