Phototransduction Pathway

The cascade of a visual signal from the photon to the perceived color. The pathway is often described as the chain of cells that the signal travels through on its way to the brain:

However, it can also be described more finely as the molecular chain of events within the Photoreceptor:

Parallel to the Phototransduction is the Visual Cycle, where Retinal goes through several steps to be regenerated after it is activated by a photon.