Farsightedness, also called hyperopia, is an eye disorder that causes objects that are close to a person to appear out of focus or blurry, while objects at a distance appear clear.
Leo hated to read. The words always seemed blurry and he had to hold books and papers at an uncomfortable distance from his face. If he had a long reading assignment, his eyes got tired, and sometimes he got a headache. Leo complained to his mother that reading was “just too hard.” His mother asked him what he meant, and he told her the words were blurry. His mother made an appointment for an eye check-up, and the doctor discovered that Leo was farsighted. His condition was corrected with prescription eyeglasses, and reading was no longer stressful.
To people with farsightedness, the words on this page would seem blurry, unless they were wearing prescription (pre-SKRIP-shun) eyeglasses or contact lenses designed to correct the problem. But if they looked up from the page to read a sign across the room, they probably could read it easily. In most cases, farsightedness occurs when the eyeball is shorter than normal. For an object to appear clear, the light passing through the eye must focus on the retina, a layer of photosensitive * cells on the back of the eye. The retina is like the film in a camera. It is where the image passing through the eye is projected and then sent along the optic nerve * to the brain. In the brain, the image is processed into what we see. If the eyeball is too short, the image that is projected onto the retina by close objects is blurred, and the person is said to be farsighted.
It can take many years for the symptoms of farsightedness to become noticeable. Eventually, people with farsightedness notice problems while reading or seeing objects that are close, whereas objects that are farther away remain clear. They also may start to get headaches after reading or doing other close work, and they may feel as if their eyes are tired. Between 5 and 10 percent of Americans are diagnosed as farsighted.
An ophthalmologist * can diagnose farsightedness and correct it easily with prescription eyeglasses or contact lenses. These lenses change the focus of the images passing into the eye so they are projected properly onto the retina. Several different types of refractive surgery can be used to correct the problem, but surgery is not as widely used as surgery to correct nearsightedness.
Many people become more farsighted as they age. They develop a condition known as presbyopia (pres-be-O-pe-a), which is Latin for “old eyes,” that causes close objects to appear out of focus. Presbyopia results because the lens at the front of the eyeball becomes thicker and less flexible as a person ages. This change causes the eye to have trouble focusing the images passing through the lens. The first sign of presbyopia may be noticed when adults pass age 40. They start to find they cannot read the newspaper as well. People joke that their arms are too short because they try holding the paper or book farther away so they can see it clearly. People with farsightedness may need stronger prescription eyeglasses once they pass age 40. People with nearsightedness may need bifocals * .
See also Eye Disorders: Overview • Nearsightedness
MedlinePlus. “Eye Wear.” U.S. National Library of Medicine. https://www.nlm.nih.gov/medlineplus/eyewear.html (accessed March 19, 2016).
PubMed Health. “Farsightedness.” U.S. National Library of Medicine. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMHT0023028 (accessed March 19, 2016).
American Academy of Ophthalmology. PO Box 7424, San Francisco, CA 94120-7424. Telephone: 415-561-8500. Website: http://www.aao.org
American Optometric Association. 243 N. Lindbergh Blvd., Floor 1, St. Louis. MO 63141. Toll-free: 800-365-2219. Website: http://www.aao.org
National Eye Institute Information Office. 31 Center Drive MSC 2510, Bethesda, MD 20892-2510. Telephone: 301-496-5248. Website: http://www.nei.nih.gov
* photosensitive means responsive to light.
* optic nerve is the nerve that sends messages, or conducts impulses, from the eyes to the brain, making it possible to see. The optic nerve is also referred to as the second cranial nerve.
* ophthalmologist (off-thal-MOLLo- jist) is a medical doctor who specializes in treating diseases of the eye.
* bifocals or multifocal (progressive) lenses are prescription eyeglasses that have lenses divided into two or more sections. The bottom section allows a person to see things clearly that are close, and the top section allows a person to see things clearly that are far away.