Retina plexiform layer. Coloured transmission electron micrograph (TEM) of a section through the inner plexiform layer of the retina. Neuronal processes (pink) make synaptic contacts with multiple other processes (red) many of which contain synaptic vesicles. The retina is the light-sensitive membrane that lines the back of the eyeball, onto which light is focused by the lens. These neurons carry information from the retina to the optic nerve, which carries it to the brain. Magnification: x5000 when printed 10 centimetres wide.