Photoreceptor can refer to: In anatomy/cell biology:Photoreceptor cell: a photosensitive cell in the retina of vertebrate eyesSimple eyes in arthropods (Ocellus), photoreceptor organ ("simple eye") of invertebrates often comprised of a few sensory cells and a single lensEyespot apparatus (microbial photoreceptor): the photoreceptor organelle of a unicellular organism that allows for phototaxis In biochemistry:Photoreceptor protein: a chromoprotein that responds to being exposed to a certain wave… (More on Photoreceptor)