Short-sightedness (near-sightedness or myopia) is the optical refractive error of the eye. It is an extremely common and often hereditary vision problem. The cause of myopia is either that the curvature of the cornea is too large (too convex) or the axis of the eyeball is longer than necessary. Because of this, the rays of light meet on the plane in front of the retina, so the image formed is not sharp. Individuals with myopia can see up close very well, however, they perceive objects in the distance as blurred. This can become a serious problem in everyday life. While driving for example, people with myopia may not always be able to perceive distances correctly or recognize road signs in time.