Images from the retina are analyzed for form/movement/color. For each point in the outside world, there is a corresponding image point on the retina in each of the two eyes. These images from the two eyes are then brought together and compared at higher stations in the visual pathway for extration of information about depth. Development of retina: the prosencephalon protrudes laterally and enlarges to form primary optic vesicles. These later invaginate to give double-walled optic cups, with a largely obliterated ventricular space between the two walls. The outer wall becomes the pigment epithelium, while the inner wall becomes the neural retina. The two are separated by the subretinal space, the residue of the ventricular cavity: structure of retina. The retina is composed five main types of neurons, segregated in to three main layers: outer nuclear layer: photoreceptors, no direct blood supply. The outer and inner plexiform layers are sites of synapses between layers.