Human eye.

The human eye is an organ of the brain that responds to light and allows for vision. The rod and cone cells in the retina are photoreceptive cells that can receive visible light and transmit this information to the brain. Eye signal details used by the brain to detect color vision, posture, depth, movement, and other features. The eye is part of the nervous system.

Similar to the eyes of other mammals, the non-image-form-photosensitive ganglion cells in the retina receive light signals that affect pupil size adjustment, regulation and suppression of the hormone melatonin, and circadian rhythm. [1]

Humans have two eyes, one on the left and the other on the right. The eyes live in bone marrow called orbits, in the skull. There are six additional muscles that control the movement of the eyes. The visible part of the eye is made up of the white sclera, the colored iris and the reader. A thin layer called the conjunctiva sits on top of this. The front part is also called the inner part of the eye.

The eye is not designed to be complete, but rather a two-piece unit, made up of the front (front) and the back (back). The inner part is made up of the cornea, iris, and lens. The cornea is clearer and more curved, and is connected to a large posterior part, made up of the vitreous, retina, choroid and white outer shell called the sclera. The cornea is about 11.5 mm wide (0.45 in), and 0.5 mm (500 μm) in diameter near its base. The back room makes up the remaining five-sixs; its diameter is about 24 mm (0.94 in). The cornea and sclera are connected to an area called the limbus. The iris is a round colored structure with a focus on the center of the eye, the pupil, which appears black. The size of the pupil, which controls the amount of light entering the eye, is adjusted by the iris' and sphincter muscles.

Light energy enters the eye through the cornea, passes through the reader and passes through the lens. The position of the lens is adjusted to the adjacent focus (residence) and is controlled by the ciliary muscle. Photons of light that fall on the retina-sensitive cells (photoreceptor cones and rods) are converted into electrical signals transmitted to the brain by the optic nerve and translated as vision and vision.

The eye is made up of three coats, or layers, covering various structures. The outer layer, known as the fibrous tunic, is made up of the cornea and sclera, which provide eye formation and support deeper structures. The middle layer, known as the vasunic tunic or uvea, consists of the choroid, ciliary body, pigment epithelium and iris. Inside is the retina, which receives its oxygenation from the choroid blood vessels (posterior) and retinal arteries (frontal).

The eye spaces are filled with aqueous jokes inside, between the cornea and the lens, and the vitreous body, something like jelly, behind the lens, filling the entire back hole. The water jug ​​is a clear liquid fluid contained in two places: the inner chamber between the cornea and the iris, and the back chamber between the iris and the lens. The lens that hangs on the ciliary body is the flexible ligament (Zonule of Zinn), which is made up of hundreds of transparent fibers that move muscles to change the shape of the living (focused) lens. The vitreous body is a clear structure made up of water and proteins, giving it a gel-like and sticky texture.