파일:Gray881.png

Original description from http://www.bartleby.com/107/225.html.

The retina consists of an outer pigmented layer and an inner nervous stratum or retina proper.

The pigmented layer consists of a single stratum of cells. When viewed from the outer surface these cells are smooth and hexagonal in shape; when seen in section each cell consists of an outer non-pigmented part containing a large oval nucleus and an inner pigmented portion which extends as a series of straight thread-like processes between the rods, this being especially the case when the eye is exposed to light. In the eyes of albinos the cells of this layer are destitute of pigment.

Retina Proper —The nervous structures of the retina proper are supported by a series of nonnervous or sustentacular fibers, and, when examined microscopically by means of sections made perpendicularly to the surface of the retina, are found to consist of seven layers, named from within outward as follows:

1. Stratum opticum.
2. Ganglionic layer.
3. Inner plexiform layer.
4. Inner nuclear layer, or layer of inner granules.
5. Outer plexiform layer.
6. Outer nuclear layer, or layer of outer granules.
7. Layer of rods and cones.