Farsightedness occurs when light entering the eye focuses behind the retina instead of directly on it. This is caused by a cornea that is flatter, or an eye that is shorter, than a normal eye. Farsightedness causes difficulty seeing up close.

Symptoms of farsightedness include blurred distance vision, eye fatigue when reading, difficulty seeing up close, eye strain and, in some cases with children, crossed eyes.

A simple technique called a refraction is used to diagnose farsightedness. Glasses or contact lenses are the most common type of treatment recommended. Refractive surgery may also be an option for adults.