Retina

The retina is a thin layer of cells at the back of the eyeball of vertebrates and some cephalopods; it is the part of the eye which converts light into nervous signals.

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The retina contains photoreceptor cells (rods and cones) which receive the light; the resulting neural signals then undergo complex processing by other neurons of the retina, and are transformed into action potentials in retinal ganglion cells whose axons form the optic nerve. The retina not only detects light, it also plays a significant part in visual perception. In embryonal development, the retina and the optic nerve originate as outgrowths of the brain.

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The unique structure of the blood vessels in the retina have been used for biometric identification.

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Eye: : This article refers to the sight organ. See Eye (disambiguation) for other usages....

Light: Light is electromagnetic radiation with a wavelength that is visible to the eye (visible light) or, in a technical or scientific setting, electromagnetic radiation of any wavelength. The three basic dimensions of light (i.e., all electromagnetic radiation) are:...

Photoreceptor: Photoreceptors are light-sensitive proteins involved in the function of photoreceptor cells. Some examples are rhodopsin in our retina, phytochrome in plants, and bacteriorhodopsin in some bacteria....