Farsightedness (hyperopia) occurs when light entering the eye through the lens is focused behind the retina instead of directly on it (refractive error). This is caused by an eye that is too short, whose cornea is not curved enough, or whose lens sits farther back in the eye than normal. Farsightedness is usually inherited: a person with one or more parents who are farsighted is likely to be farsighted as well.

See information about eye anatomy and function.

Many people are born farsighted. Some outgrow it as their eyes grow and develop. Children who do not outgrow farsightedness are often able to accommodate for the condition-their eyes work harder to focus and make up for the refractive error.

With age, the eyes lose their ability to accommodate for refractive errors, and farsightedness becomes more apparent. Everyone slowly loses the ability to focus his or her lens, usually around age 40. People who are nearsighted (myopic), farsighted (hyperopic), or perfectly focused for distance (emmetropic) will all eventually lose the ability to focus on near objects. This is called presbyopia.

In rare instances, diseases such as retinopathy, eye tumors, and lens dislocation can also contribute to the development of farsightedness.