الخميس، 11 أكتوبر 2012

العين The eye

The eye eye




Hardly be eye round only at the forefront of where there is a slight bulge. Showing the eye in children about three-quarters of an inch increase to an inch in an adult. From this it is clear that the eye does not grow much with the growth of the body. Eye consists of the following parts:

 


    Cellular mucous membrane (epithelium Epithelium)
    A thin protective layer of cells covering the surface of the cornea.

    Cornea Cornea
    Strong, transparent fabric, curved, spherical, play the role of a window of the eye. The cornea is the main focus of the eye. When light enters the eye refracts by Cornea.

    Iris Iris
    Colored part visible to the eye, which expands and reduces the central aperture of the eye.

    Iris - human eye - the pupil Pupil
    Central aperture that allows light to pass through to the inside of the eye.

    Lens Lens
    Floppy disk frosted transparent, biconvex useful in focus, and is located behind the iris. Controlled muscles on the shape of the lens automatically focus. Whenever we age less flexibility and Mtatitha lens, and this condition is called "Presbyopia vision presbyopia" which makes it difficult to focus on nearby objects such as a newspaper or a book. This is why some need for reading glasses after the age of forty.

    Natural lens
   


    Lens with age

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