The light sensitive cells (rods and cones) in the retina.
Photoreceptor cells are the light sensitive cells in the retina that absorb light and convert it into an electrical signal that is passed to the brain through the optic nerve (see Phototransduction). There are two types of photoreceptor cells: rod and cone cells. Rod cells are responsible for black-and-white, peripheral and night vision. Cone cells are mainly responsible for fine visual detail (see Visual Acuity), color, central and day vision. There are three types of cone cells, each of which detects colored light of a different wavelength (red, green and blue). In humans, rod cells are mainly found in the retinal periphery while cone cells are concentrated in the central portion of the retina (macula). Toxins, produced as byproducts of light detection by photoreceptor cells, are removed and/or recycled by the adjacent RPE cells.