Enables protein homodimerization activity. Acts upstream of or within several processes, including detection of light stimulus involved in visual perception; protein complex oligomerization; and retina development in camera-type eye. Located in photoreceptor outer segment membrane. Is expressed in photoreceptor layer; photoreceptor layer outer segment; and retina. Human ortholog(s) of this gene implicated in retinitis pigmentosa 7. Orthologous to human ROM1 (retinal outer segment membrane protein 1). [provided by Alliance of Genome Resources, Apr 2022]