Contact Lenses

Why It Is Done

Contact lenses can correct nearsightedness (myopia), farsightedness (hyperopia), astigmatism, and presbyopia. Lenses that correct astigmatism are called toric lenses. They may need to be custom-made and may cost more than ordinary contact lenses.

Contact lenses may be used by people who have had cataract surgery and couldn't have an artificial lens implanted in the eye. They may also be used to treat eye diseases, such as keratoconus or damage to the cornea caused by injury or infection.

Most people choose to wear contacts because of the convenience and because they prefer the way they look without eyeglasses.

Bifocal contact lenses have been developed for people who have both nearsightedness and presbyopia. Bifocal lenses provide correction for both near and distance vision on each lens.

If bifocal contact lenses will not work for you, your doctor may recommend monovision. With monovision, you wear a contact lens that corrects for near vision in one eye and a lens that corrects for distance vision in the other eye. Many people who try monovision can adjust to it. Monovision has some drawbacks, though. Each eye must work more independently, making good binocular vision difficult, which can cause problems with depth perception. You may have to adjust your gaze more often to allow one eye or the other to see properly.

In other cases, your doctor may recommend using reading glasses in combination with contact lenses that correct for distance vision.

People who are generally well-suited to wearing contact lenses (hard or soft) include:

• People who have a lot of trouble seeing things at a distance and need vision correction all the time. People who wear eyeglasses only part of the time are less likely to wear contacts successfully.
• Those with strong motivation. You have to be willing to tolerate minor discomfort during the break-in period and to learn and use proper methods of storing and handling your lenses.

People who perform work or play sports in which glasses are inconvenient or dangerous often choose contacts over glasses.

Contact lenses may not be a good choice if you:

• Are not able or are not willing to care for the lenses properly.
• Would have a hard time handling the lenses (for example, if you have severe arthritis in your hands or another problem that would make it hard for you to insert, remove, and clean the lenses).
• Have certain medical conditions such as uncontrolled diabetes or hyperthyroidism. Allergies, asthma, and other chronic respiratory disorders may make it difficult to wear contacts.
• Have dry eyes or problems with the cornea. People who have Sjögren's syndrome (a condition that causes a lack of tears and dry eyes) often are not able to wear contacts. People who have chronic or recurrent infections or sores on the cornea cannot wear contact lenses.
• Have a job that exposes you to particles, chemical fumes, or other vapors that may be absorbed by or stick to the lenses (such as dust and dirt, paint, spray chemicals, or hair spray).

Infants and children

Infants and children usually do not wear contact lenses, except to treat some medical conditions. Many teenagers wear contacts. But they and their parents must accept the need for frequent changes in the prescription until the eyes stop changing in the late teens or early 20s.