SHORT-SIGHTEDNESS (MYOPIA)

This results when the lens curvature is too large or eyeball too long, light  rays entering the eyes are refracted more than necessary. Consequently, light is focused in front of the retina. By the time light stimulates the retina it has diverged from the focal point of the lens. The image received is blurred. The condition is called short-sightedness because objects near the eyes are less out of focus than those further away. This is because the light rays from near objects require greater refraction to be focused on the retina than rays from distanced objects. Since the lens in myopic eye refracts light excessively, distant objects appear more blurred than near ones. It can be corrected by placing concave lens, refracts light rays in such a way the rays diverge slightly from their original path. The lens of the myopic eye now refracts the diverged light rays into focus on the retina.