This gene encodes a member of the Vsx (visual system homeobox) family which belongs to the larger PRD homeobox class. The encoded protein is required for eye organogenesis and controls retinal development. Disruption of this gene is associated with ocular retardation J (orJ), a mouse disease which causes microphthalmia, retinal degeneration and optic nerve aplasia. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Aug 2014]