A focusing (refractive) error of the eyes that makes it difficult to see distant objects clearly; also known as myopia. In most cases of nearsightedness, the eyeball is overly long from front to back. As a result, the distance is too great for the lens to focus incoming light rays on the retina (the thin, light-sensitive layer of nerve tissue at the back of the eye that relays visual information to the brain). Nearsightedness can also result from too much focusing power in the lens and cornea (the clear covering on the exposed surface of the eye). In both types of nearsightedness, distant objects are blurry while close ones are clear.
A vision problem characterized by the inability to focus clearly on objects that are far away.
A state in which either one or both eyes are unable to achieve normal focus, resulting in distant objects appearing blurred and unclear. This condition is also known as myopia.