The retina, located in the back of the eye, contains several layers of photoreceptor cells (called rods and cones).
The optical system of the eye creates an image of the visual world on the retina in the same way as an old fashioned camera did with film.
Light incident upon the retina initiates a cascade of chemical and ultimately electrical events that are communicated to the brain via the optic nerve, where these images are interpreted (resulting in visual perception).
The retina is part of the central nervous system, and consists of brain tissue.
Will this order be shipped to the United States or Canada?