Farsightedness or hyperopia, 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. Farsighted people usually have trouble seeing up close, but may also have difficulty seeing far away as well.

Young people with mild to moderate hyperopia are often able to see clearly because their natural lens can adjust, or accommodate to increase the eye's focusing ability. However, as the eye gradually loses the ability to accommodate (beginning at about 40 years of age), blurred vision from hyperopia often becomes more apparent.