Write a note on the retina.
The innermost layer of the wall of eyeball is the retina. It is composed of several layers of cells the photoreceptor layer contains rods and cones, the intermediate layer has bipolar neurons, which synapse with retinal ganglion cells and their axons bundle to form optic nerve. The rod cells contain rhodopsin while the cone cells contain iodopsin. The point in the retina where the optic nerve leaves the eye, is called as blind spot. Lateral to the blind spot, there is a yellowish pigmented spot called macula lutea with a central pit called the fovea. Fovea is the region where cones are densely packed and the vision is the sharpest.
