Plays a critical role in eye formation by regulating the initial specification of retinal cells and/or their subsequent proliferation. Expressed at stage 4 in the ectoderm, at stage 6 in the anterior most neural plate, at stage 7 and 8 in the anterior neural fold and at stage 9-10 in the evaginating optic vesicles. At stage 14, highly expressed in developing retina and in infundibulum region. Belongs to the paired homeobox family. Bicoid subfamily.