Light enters the eye and hits the retinal pigmented epithelium (maroon). This excites rods (grey) and cones (blue/red). These cells synapse onto bipolar cells (pink), which stimulate ipRGCs (green) and RGCs (orange). Both RGCs and ipRGCs transmit information to the brain through the optic nerve. Furthermore, light can directly stimulate the ipRGCs through its melanopsin photopigment. The ipRGCs uniquely project to the superchiasmatic nucleus, allowing the organism to entrain to light-dark cycles.