Enables opsin binding activity. Involved in several processes, including protein localization to ciliary membrane; regulation of organelle assembly; and regulation of platelet-derived growth factor receptor-alpha signaling pathway. Acts upstream of or within several processes, including animal organ development; morphogenesis of a polarized epithelium; and plasma membrane bounded cell projection organization. Located in several cellular components, including ciliary base; microtubule organizing center; and non-motile cilium. Part of intraciliary transport particle B. Orthologous to human IFT20 (intraflagellar transport 20). [provided by Alliance of Genome Resources, Apr 2022]