It usually decreases the severity of change by the late teens, but it can sometimes continue to get worse into the mid-twenties. Myopia occurs when an eye is too long or too strong for the light-bending ability of the cornea's curvature. Light rays entering the eye do not come to a sharp focus on the retina at the back of the eye. Instead, they focus farther forward, producing a blurred image. The more myopic, the more blurred distant objects appear, the higher your eyeglass prescription and the thicker your glasses needed for correction.
Hyperopia is the medical term for farsightedness.
This occurs when an eye is too short for the light-bending ability of the cornea's curvature. Light rays entering the eye do not come to a sharp focus on the retina at the back of the eye. Instead, they focus farther backward, producing a blurred image. In young persons with high degrees of hyperopia or in individuals over the age of 45, this compensation ability may be inadequate to produce clear images and vision will be blurred. The two different curves in such a corneal surface each bend light rays to a separate focus point.