Enables intracellular cyclic nucleotide activated cation channel activity. Acts upstream of or within retinal cone cell development. Located in photoreceptor outer segment and plasma membrane. Is expressed in eye; gut; and male reproductive gland or organ. Used to study achromatopsia 2. Human ortholog(s) of this gene implicated in achromatopsia 2 and color blindness. Orthologous to human CNGA3 (cyclic nucleotide gated channel subunit alpha 3). [provided by Alliance of Genome Resources, Apr 2022]