Cones

The conical light-sensitive receptor cells of the retina that function in color vision and in the perception of fine detail; composed of an outer segment (containing the photoreceptor molecule iodopsin, which is composed of photopsin and retinene), inner segment, cell body, and synaptic region; about 6½ to 7 million per eye, much fewer than the number of rods; densest accumulation is in the macula and, especially, the fovea; absent in the optic disk (optic nerve head).