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what is the structure of our eye?
The cornea is located at the front of the eye and is the transparent window through which light first passes before traveling through an opening called the pupil.

The iris appears as the colored part of the eye and is responsible for regulating the size of the pupil, which in turn influences the amount of light that enters the eye. Finally, at the back of the eye lies the retina, a multilayered structure consisting of a diverse array of cell types, which receives visual stimuli from the environment and transmits this information to the brain, via the optic nerve for further processing.
The innermost layer (closest to the back of the eye) is called the iris pigment epithelium, or IPE for short.
The cells of this layer appear as tiny cubes and are stacked in a compact and orderly arrangement, much like bricks. Furthermore, as the name suggests, these cells appear pigmented. The top layer is referred to as the iris stroma, which consists of less orderly and more loosely arranged cells.

There are several different cell types present in the stroma, including a specialized population of pigmented cells called melanocytes. Melanocytes are cells that synthesize pigment (referred to as melanin) and originate from an embryonic structure called the neural crest.
Light enters the eye through a small hole called the pupil and is focused on the retina, which is like a camera film. Eye also has a focusing lens, which focuses images from different distances on the retina. The colored ring of the eye, the iris, controls the amount of light entering the eye. It closes when light is bright and opens when light is dim. A tough white sheet called sclera covers the outside of the eye. Front of this sheet (sclera) is transparent in order to allow the light to enter the eye, the cornea. Ciliary muscles in ciliary body control the focusing of lens automatically. Choroid forms the vascular layer of the eye supplying nutrition to the eye structures. Image formed on the retina is transmitted to brain by optic nerve. The image is finally perceived by brain. A jelly like substance called vitreous humor fill the space between lens and retina. The lens, iris and cornea are nourished by clear fluid, aqueous humor, formed by the ciliary body and fill the space between lens and cornea. This space is known as anterior chamber. The fluid flows from ciliary body to the pupil and is absorbed through the channels in the angle of anterior chamber. The delicate balance of aqueous production and absorption controls pressure within the eye.


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