Binds to the 37-bp core of the locus control region (LCR) of the red/green visual pigment gene cluster (By similarity). May regulate the activity of the LCR and the cone opsin genes at earlier stages of development (By similarity). Dispensable in early retinal development (PubMed:17919464). Expressed in the postnatal retina (at protein level) (PubMed:17919464). In the adult, expressed exclusively in the cells of the neural retina with expression restricted to postnatal cone bipolar interneurons (PubMed:15838724). Expressed at P5, solely within the inner nuclear layer (INL) of the central neuroretina. By days P6 and P7, expression expands peripherally during neurogenesis. By P12, expression is restricted to the outer margin of the INL and reaches the outer periphery of the neuroretina. At embryonic day 14.5 ocular morphology is normal as is expression and localization of retinal transcription and cell cycle regulatory proteins. Belongs to the paired homeobox family.