Eye

The eye receives light as input (omg). The cones (detail, colour, need bright light) and rods (can operate in dim light) are located at the back of the retina.

The information goes through bipolar cells to the retinal ganglion cells (RGCs). There are three kinds of RGC:
 * Photosensitive RGCs (pRGCs) connect to the suprachiasmatic nucleus, and are not part of the visual pathway.

The axons of the M and P RGCs form the optic nerve, and proceed towards either the LGN or the Superior collicus. (See: visual pathway).
 * The magnocellular cells get input primarily from rods, the parvocellular from cones.