Rods and cones and the problem of visual excitation.
D000818:Animals; D006801:Humans; D008854:Microscopy, Electron; D010786:Photoreceptor Cells / Q000166:cytology / Q000502:physiology*; D012160:Retina / Q000033:anatomy & histology; D012168:Retinal Pigments; D011984:Sensory Receptor Cells; D013569:Synapses; D014785:Vision, Ocular
D012168:Retinal Pigments