Compare and contrast the rod cells and the cone cells in the retina of the human eye.

Rods and cones are both photoreceptors located in the retina of the human eye. A photoreceptor is highly specialized type of nerve and in this case is used to detect and monitor vision.

A rod is called a rod because under close examination the shape is actually has a cylindrical shape like a rod or tube. Within the the rod, there are thousands of optic disks, which contain proteins that absorb light and eventually transmit this to the brain. Rhodopsin is the protein which is contained within these optic disks.

A cone has similar features to a rod, in that is also is composed of layers of optic disks that have protein. Similar to its name, the cone photoreceptor is in the shape of its namesake, a cone, or conical in shape. Photpsin is the protieng which is contained with this optic disks.

The processes are very similar in both rods and cones for their basic process of interacting with light waves, in that the light enters and is absorbed by the particular proteins of the rod or cone and then that information is coordinated and sent to the brain.

A huge contrast is related to the number of each of rods (approximately 120 million) to cones (approximately 6 million) in an average retina. Also the concentration and location of the rods and cones is very different. The rods are found along the top and bottom parts of the retina, called the periphery, whereas the cones are found mostly concentrated in and around a dimple called the fovea, in approximately the middle to upper-middle portion of the retina.

Rods do not have the ability to detect color, but are hyper-sensitive to light and as such are a 1,000 times more sensitive to light than cones. Rods are really good at telling us that light is there. Rods also have a very slow time to recover or be able to adapt to new light circumstances.

Cones have a fast recovery time and are also divided into three different types, red, green and blue, in an approximate ratio of 6:3:1