It involves many different subsystems and interacts with nearly every other part of the brain. When light is focused, even through a pinhole camera without a lens, light is bent 180 degrees, so the image is projected upside down. The same thing happens in the eye, so the image on the retina is upside down, and so is the neuronal image of objects and space. Rods are thin linear cells which are extremely sensitive to even small amounts of light or changes in light. They are fairly evenly distributed throughout the retina, except in the center, which is dominated by cone-shaped cells.
Cones are slightly conical in shape and are more sensitive to bright light.
Cones are responsible for finely detailed vision. They are also divided into 3 different types which contain specialized pigments, allowing the cell to be maximally sensitive to certain frequencies or colors of light. The three types of cells are most sensitive to either reddish, bluish or yellowish light. The retinal tissue is generally considered to actually be brain tissue. So, it is the only part of the brain which is located outside of the skull.