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.
Hyperopia is detected with a vision test called a refraction. Very young patients may require cycloplegic eyedrops prior to this test so that they are unable to mask their farsightedness with accommodation.
The treatment for hyperopia depends on several factors such as the patient's age, activities, and occupation. Young patients may or may not require glasses or contact lenses, depending on their ability to compensate for their farsightedness with accommodation. Glasses or contact lenses are required for older patients.
Refractive surgery is an option for adults who wish to see clearly without glasses. LASIK, clear lens replacement, LTK and intraocular contact lenses are all procedures that can be performed to correct hyperopia.
Illustrations by Mark Erickson
With acknowledgement to St. Lukes Eye Hospital.