Contact lenses are small plastic or silicone discs shaped to correct an eyesight problem such as nearsightedness, farsightedness, presbyopia, or astigmatism. These are called refractive errors. They may also be used by people who have had surgery for cataracts.
After your doctor tests your vision, he or she will write a prescription for the lens you need. Your prescription may change over time.
Contacts are placed directly on the eye, where they float on a film of tears in front of the cornea. Correct design and fitting of the lenses are essential for comfort, safety, and accurate correction.
Improvements in contact lenses have made them more comfortable and easier to wear. Millions of people wear contact lenses, and most wear soft lenses. For these people, contact lenses offer a relatively safe and effective way of correcting vision problems.
Several types of contact lenses are available to correct nearsightedness. Contact lenses are needed after cataract surgery if an artificial lens cannot be implanted in the eye.
What To Expect After Treatment
With most hard contact lenses, there will be a 2- to 4-week break-in period during which you wear the lenses for increasingly longer periods of time each day. Soft contact lenses usually take less time to break in.
The care of contact lenses varies according to the type of lens. Care may range from minimal (disposable extended-wear soft lenses) to extensive (conventional soft lenses). It is important to follow directions for lens care carefully to avoid vision-threatening complications. If you have a hard time following the cleaning steps, tell your eye care professional. You may be able to simplify the cleaning steps, or you may want to switch to disposable 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 surgery for cataracts if the natural lens of the eye was removed. 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.
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:
Contacts are preferred over glasses for people who perform work or play sports in which glasses are inconvenient or dangerous.
Contact lenses may not be a good choice if you:
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.
How Well It Works
Almost everyone who is nearsighted can be fitted with contact lenses. Some types work better than others to correct specific problems.
Minor but bothersome side effects of contact lenses are common. But the overall risk of infection and other vision-threatening complications is low.
Problems sometimes caused by wearing contact lenses include:
Some problems are more common with certain types of lenses. You may be able to avoid some problems by cleaning your lenses more often, not wearing your lenses overnight or, in some cases, changing the type of lenses you wear.
What To Think About
After going through the time and expense of fitting contact lenses, some people find that they are not able to wear them. Allergies, dry eyes, discomfort during the adaptation period, and the "hassle factor" are frequent causes of not being able to wear contacts.
It may take time to find the type of contact lens and a wearing schedule that is best for you. A wide variety of lenses is available. When you choose a lens, think about cost, comfort, quality, cleaning time, and safety. Look for an eye care professional who is willing to work with you to select the best type of lens for your needs and lifestyle.
Many people have problems with their contacts because they don't follow instructions on wearing time, disinfection, and other cleaning and care practices. For best results and to protect your eye health, follow all instructions closely.
Daily disposable lenses are the safest soft contact lenses for your eyes.
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