Farsightedness is a common eye problem. Typically, it is caused by the ball of the eye being too short, so that the lens focuses an image behind the retina, rather than at the retina. Often, children who suffer from this condition outgrow it as they grow and their eyes expand in size. The official medical term is hyperopia. Its opposite is nearsightedness, or myopia.
People with farsightedness can focus on objects that are far away, but can't bring objects closer to them into focus. Reading, watching television, and working on a computer are all difficult, uncomfortable, or impossible for them without corrective lenses.
The eye has to react to the input it takes in, so the muscles controlling the eye squeeze or relax the lens, which changes its shape to focus the light rays. Over time, the lens may become less flexible, or the muscles less effective. As a result, some people develop farsightedness in later life.
Correcting this condition is simply a matter of adding a lens in front of the eye's lens that adds convergence to the light rays, so that when they reach the retina, they form an image. The curvature of the corrective lens is dependent on the extent of the farsightedness. This exact curvature is specific to each individual, and may be different for each eye. These figures, the parameters of each lens, are your prescription for glasses or contacts.
Hyperopia can now be corrected with a laser surgery process called Lasik, or laser in-situ keratomileusis. In this procedure, a small piece of the lens is peeled back, then the lens is reshaped with a laser beam and the peeled-back piece is replaced to cover the lens. The lens is reshaped to be more rounded or convex. Farsightedness occurs in about twenty-five percent of the population.