Contact lenses are used to help correct vision problems. Although they do not fix the problem, they are placed over the eye and assist the wearer in seeing more clearly. These thin lenses lay over the cornea, and correct visibility problems. Contact lenses are available through a prescription from a licensed physician.
Function
Contact lenses are used to replace eyeglasses. They have the same function as eyeglasses, and they correct several vision conditions diagnosed by a physician. Contact lenses are used to correct nearsightedness, farsightedness, astigmatism and presbyopia. Some contact lenses are also used to change the color of the eye. In some cases, a contact lens prescription is used to treat scarring or uneven corneas, which cause blurred vision.
Types
There are three main types of contact lenses: hard, gas permeable and soft lenses. The hard, rigid lenses are more irritating to the eye, because they inhibit the amount of oxygen that reaches the cornea. Because of the irritation, the hard or rigid lenses are not used as often. Gas permeable lenses are rigid, but these types of lenses are porous, so air is able to pass through to the cornea. These lenses are the preferred hard lens. Finally, the soft lenses incorporate water. They are soft and flexible, and they are the most commonly used contact lens. The water enables oxygen to reach the cornea, so they are less irritating to the eye.
Risks
The risks for contact lenses are mostly movement of the lens on the eye. The lens can sometimes slip off the cornea and fall into the lid of the eye. There is also a possibility that the contact lens will fall off the cornea, and you aren't able to find it. Misuse of daily contact lenses, like wearing them more than a day, can lead to irritation and red eye. This can lead to an infection in the eye.
Care
When a doctor prescribes contact lenses, it's important to follow the physician's instructions. Proper care of contact lenses limits the chance for infection and irritation in the eye. Contact lenses need to be cleaned and sterilized before wearing them. The wearer also needs to clean the contact lens case. Do not mix cleaning solutions for contact lenses, since individual cleaners can interact with each other.
Use
Using contact lenses includes inserting them properly and keeping hands clean. Always wash hands before inserting a contact lens. Place the lens over the cornea softly. The lens attaches to the eye using surface tension. If the eye is red or infected, use eyeglasses instead. Lenses are disposed after a certain amount of time. A physician will tell you when to dispose of contact lenses and replace with a new pair.
