This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Optic nerve hypoplasia (ONH), congenital underdevelopment of one or both optic nerves, was once thought to be rare but is now recognized as a major etiology of subnormal vision in children and is a leading cause of congenital blindness at CHLA. This study is designed to provide preliminary data about the factors that may be involved in the formation of ONH prior to birth. It is also designed to correlate those factors with the severity of the disease and its associated medical conditions.