Acts as a transcriptional regulator (By similarity). Mediates the differentiation of V2a interneurons (By similarity). Plays a role in eye development and organization of the neuroretina (PubMed:9203137, PubMed:17919464). Expressed 12 hours post-fertilization (hpf), concomitantly with the appearance of the optic vesicles. At 18-20 hpf expressed in presumptive neural retina. At 24 hpf when the lens are formed, expression in the eye is restricted to the neural retina. At 48 hpf, after completion of the retinal differentiation, expression is restricted to the germinal cells at the margin of the retina and to paired parasagittal locations in the dorsal mesencephalon and rhombencephalon. Morpholino knockdown causes a decrease in eye size and an increase in expression of vsx1 and ccnd1 at 24 hours post-fertilization. Belongs to the paired homeobox family.