The exact cause of nearsightedness is unknown, but two factors may be primarily responsible for its development, heredity and visual stress. There is significant evidence that many people inherit nearsightedness, or at least the tendency to develop nearsightedness. If one or both parents are nearsighted, there is an increased chance their children will be nearsighted.Even though the tendency to develop nearsightedness may be inherited, its actual development may be affected by how a person uses his or her eyes. Individuals who spend considerable time reading, working at a computer, or doing other intense close visual work may be more likely to develop nearsightedness.