When the light rays converge at a point in front of the retina and then divert to form a blurred image on it, the defect is known as
Myopia occurs when the eyeball is too long, relative to the focusing power of the cornea and lens of the eye. This causes light rays to focus at a point in front of the retina, rather than directly on its surface. Nearsightedness also can be caused by the cornea or lens being too curved for the length of the eyeball.