Nearsightedness, also referred to as Myopia, is when light entering the eye is focused incorrectly, making distant objects appear blurred. Nearsightedness is a type of refractive error of the eye. If you are nearsighted, you have trouble seeing things that are far away.
Farsightedness, also referred to a Hyperopia, is the result of the visual image being focused behind the retina rather than directly on it. It may be caused by the eyeball being too small or the focusing power being too weak.