Photoreceptor can refer to: In anatomy/cell biology: Photoreceptor cell: a photosensitive cell, most commonly referring to a specialized type of neuron found in the retina of vertebrate eyes that's capable of phototransduction Ocellus (invertebrate photoreceptor): a photoreceptor organ ("simple eye") of invertebrates often comprised of a few sensory cells and a single lens Eyespot apparatus (microbial photoreceptor): the photoreceptor organelle of a unicellular organism that allows for photota… (More on Photoreceptor)