The Remarkable Human Eye[caption id="attachment_2169" align="alignright" width="424"] The Structure Of The Human Eye[/caption]As you can see by the illustration on the right the human eye is a very complex part of our anatomy. Most of us are aware of the pupil in our eyes and the iris of our eye, but beyond that we know little about the structure of the eye. Here is a brief description of each of the part of the eye to help us understand how the human eye works:
- Anterior Chamber - is filled with Aqueous, a water like fluid, which is turned over every 100 minutes;
- Conjunctiva - a thin lining over the white part of the eye which produces mucous to lubricate the eye;
- Cornea - the transparent outer window of the eye which is the primary focusing element of the eye. The outer layer of the cornea is the epithelium whose primary job is to protect the eye while the inner layer of the cornea allows light to pass into the eye;
- Pupil - controls how much light enters the eye by opening and closing;
- Iris - is the part of the eye which gives the eye its color and functions like the diaphragm of a camera, dilating and constricting the pupil to control the amount of light allowed to enter the eye;
- Lens - is immediately behind the iris that focuses light rays on the retina;
- Retina - is a membrane which lines the back of the eye and contains the photoreceptor cells. These cells react to the presence and intensity of light and send an impulse to the brain through the optic nerve;
- Macula (not shown) - is a part of the retina, is very sensitive and responsible for our reading vision. It is also responsible for color vision;
- Optic nerve - takes the information from the retina and transmits it to the brain where it is converted into a visual image. The optic nerve has approximately one million nerve fibers;
- Sclera - is the tough wall of the eye;
- Vitreous humor - is a jelly like substance that fills the body of the eye. This is where we sometimes get those "floaters".
Video On How The Human Eye Works
How Do You See?When you look an object light is reflected off of it and enters your eye through the pupil. The iris adjusts the opening size of the pupil depending upon how strong the light rays are. The lens of the eye then focuses the light rays on the retina which is full of light sensitive neurons called photoreceptors which in turn turn the light rays into electronic signals which are transmitted to the brain through the optic nerve. The eye works very much like a camera where each part plays an important role in providing clear vision. For example the cornea takes divergent light rays and bends them through the pupil, then through the lens which focuses the light on the back of the eye. The back of the eye is like the film in a camera which captures the light rays with photorecptor cells, converts them into electrical impulses and then they are sent to the brain through the optic nerve.
This Video Shows You How We See