Rods and Cones
 

•  Rods and cones - are the receptors that receive light and color.  They translate this information to nerve impulses and send them to the brain.  In the brain, the signals are converted back from nerve impulses to images.  Rods and cones cover the entire retinal surface.
• Rods - allow us to see black and white, and are mainly for night vision.
• Cones - allow us to see color, and are active when there is sufficient light.