Through the eyes, we see things in a moderate form, but in reality, the lens creates a microcosm, which is reversed on the sensitive spot of the retina. This image, with its colors in the retina, is translated into electrochemical signals that are transmitted by the nerve of the eye to the brain for treatment. Each eye sees an image of something and the brain combines the two pictures, so we see a stereoscopic image of the object.
Colors are seen by a specific type of cell sensitive to light colors, which is a conical cell: a type of those conical cells that sees red, a type that sees blue and a third type that sees green. This is enough for the eye to distinguish all the colors you see.
The human eye consists of three main layers:
The sclera, located outside, is made up of connective tissue; it protects the eye and is rich in blood vessels. The front part of this layer is transparent, the cornea, does not contain blood vessels, so it takes the food and oxygen it needs from the aqueous humor that is excreted from the ciliary body.
The Choroid, and is laying between the retina and the sclera. It contains blood vessels that deliver oxygen-carrying blood to the retina. It is rich in melanin pigment that absorbs the excess of light rays that traverse the retina, prevents its reflection, and causes clarity of vision.
The retina, the choroid is lining from the back and sides but does not reach the front, and the retina consists of two sheets:
External pigment paper