Contact lenses are placed in your eyes to help correct vision problems caused by an abnormal shape of the eye. They are small, curved pieces of plastic shaped to fit your eyes. Contact lenses float on top of a thin layer of tears on the cornea, which is the clear outer layer on the front of the eye. Contact lenses can correct most of the vision problems that glasses correct. They can also correct some problems that glasses cannot.
Contact lenses may be more practical than eyeglasses if you play sports or work at jobs where glasses could get in the way. Also, contacts give better side vision than glasses do. You may choose contact lenses simply because you prefer the way you look without wearing glasses.
Contact lenses may provide better vision than glasses if you:
You may find it hard to wear contact lenses if you have:
Gas permeable contact lenses
The plastic used for gas permeable (GP) lenses lets oxygen reach the cornea. GP lenses may be called hard lenses because they are stiffer than soft contact lenses.
GP lenses have some advantages over soft lenses:
The main disadvantage to GP lenses is that they are harder to get used to than soft lenses.
Soft contact lenses
Soft lenses are made of material that absorbs fluid. Soft lenses are very flexible. They are usually more comfortable than GP lenses, and you can adjust to wearing them more easily. They are also less likely to fall out than the GP lenses. Most people who wear contacts wear soft contact lenses.
The disadvantages of soft contact lenses include:
Daily-wear soft contact lenses must be removed and cleaned every night. Daily disposable contact lenses should be thrown away after wearing them for one day. Extended-wear soft contact lenses are very thin but contain a lot of water, which lets oxygen reach the eyeball even if you wear them for long periods. Your eye care provider will advise you not to wear your contacts when you sleep, even with extended-wear contacts. Wearing the lenses too long causes eye irritation and greatly increases the risk of a serious eye infection that could cause blindness.
Disposable contact lenses
Disposable contact lenses are soft contact lenses that you wear for a short period of time and then throw away and replace with new ones.
There are different types of disposable contacts. Some are used for one day only and then thrown away. You put in new lenses every morning and discard them at night. Others are worn each day, removed and disinfected each night, and discarded after 1 week to 3 months, depending on the specific lens. People may try to wear the lenses longer than the recommended time or reuse the lens to save money. Doing this greatly increases the risk of eye irritation or serious eye infection.
The advantages of disposable lenses are:
The main disadvantage is that disposable lenses cost more over time than other kinds of contact lenses.
Bifocal contact lenses
Bifocal contact lenses have both your distance prescription and your reading prescription in each lens. They are available as gas permeable or soft lenses, and as daily wear or extended wear types. You may need to try bifocal contact lenses to decide if they are right for you.
You need a thorough eye exam by an eye doctor who will:
Slight discomfort when you first start wearing contact lenses is normal. If you have any pain in your eyes, see your eye care provider. You should have regular checkups of your eyes as recommended by your eye care provider. If you have any problems, talk about them with your eye care provider.