Nearsightedness or myopia is a condition in which close objects are seen clearly, but distant objects appear blurred. Nearsightedness results from a lengthened eyeball which is more oval than round.
The increased length of the eye makes it impossible for the eyes' natural lens to change its shape sufficiently to focus light from a distant object onto the retina. As a result, when looking at something in the distance, light rays are brought to focus just in front of the retina and vision is blurred.
Nearsightedness is most commonly a hereditary condition which ususally develops in children around the age of eight or nine. Myopia tends to worsen during its early stages and then stabilize during the adult years. Eye glasses, contacts, and sometimes surgery are used to treat myopia. The curve of the lens in the glasses or contacts compensates for the longer shape of the eye by bending the light rays to focus properly on the retina.