Complex structures of an eyeball - By: AdamDouglas

The eye is a very crucial organ of the body. But not all people know detailed parts of an eyeball and how it works. In fact, the eyes are spheres about an inch in diameter. They are self lubricating, self cleaning and well protected. Of course, the fundamental task of the eyes is to focus images entering the eyes. The eyes can further convert the received images into nerve impulses. After that, the optic nerve will send the generated nerve impulses to the brain for final interpretation. The eyes are very sensitive that they can distinguish between images only one ten thousandth of an inch in apart.

The powerful function of the eye comes actually from different structures of an eyeball working together in cooperation. The cornea acts as the window at the front of the eye. This part is responsible for bending or refracting light before it is passed through the lens. Commonly referred as the while part of the eye, the sclera forms the round wall of the eyeball. The iris of the eye is commonly used to describe one¡¯s eye color such as brown or blue. In detail, the iris sits behind the cornea and controls the amount of light entering the eye.

Another element of an eyeball is the pupil, which is the black hole in the center of the iris. In an environment with low light, the muscles of the iris adjust the pupil to open wide or dilate. And the pupil will become smaller in bright light. Sitting behind the pupil, the lens is responsible for focusing light onto the retina. It is a flexible bag of clear protein and surrounded by a thin membrane called capsule or capsule bag. The retain lining the back half of an eyeball registers light images and sends them to the brain through the optic nerve consisting of a bundle of nerve fibers. It is commonly said that the eye works much like a camera. In this case, the retina can be interpreted as the film.

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