Retina - is the inner membrane of the eyeball. It is part of the nervous system and is the first department of the visual analyzer. In the retina, the light energy is converted into nerve impulses and is the primary analysis of visual information.
The upper layer of the retina - the pigment. It absorbs the light, reducing its diffusion inside the eye, and it also produced visual material. The next layer contains the processes of the retina - rods and cones. Spines contain visual substance (visual purple) - rhodopsin (rods) and iodopsin (cones).
The rods and cones send jitters farther than bipolar cells, and these in turn ganglion cells. Spines of these cells are collected in the optic nerve.
Optically active part of the retina can be seen when examining the eye. It is called the fundus. In the fundus may be considered vessels, optic disc, as well as a yellow spot. The yellow spot - an area of the retina, where concentrated the maximum number of cones, are responsible for color vision. Single out the blind spot of the retina, an area of the location of the optic nerve, which contains no cells of the retina, so when you hit it on the light rays, the function of this region does not.
Of all the diseases of the eye for retinal disease accounts for about 1%. Most often occur in the retina of the dystrophic and inflammatory processes. May result in retinal eye injuries. The state of the retina affected by cardiovascular disease, endocrine disease. In the retina may develop cancerous processes.