Contact lenses are small, disc-shaped pieces of plastic that are placed on the surface of the eye. They are worn primarily to provide vision correction for several eye problems. Contact lenses are often chosen as an alternative to eyeglasses because they may be more aesthetically pleasing or convenient, especially in situations where glasses are a hindrance. If you are considering contacts, learn about your choices before you buy them.
Materials
Hard contact lenses are made of plexiglass or lucite. While hard lenses are still available, most people choose soft contact lenses. New wearers of hard contact lenses need to get used to wearing them. The adjustment usually takes two to four weeks. Soft contact lenses are made of plastics that are gel-like. These lenses are much more comfortable than hard lenses and take less adjustment time. Gas permeable lenses are made of hard plastics that allow gases to pass through the lens material, keeping the eye properly oxygenated.
Uses
Contact lenses are used for a variety of eye disorders, including near sightedness, far sightedness and astigmatism. They are placed on the front of the eyeball and float on the cornea. The lenses correct the refraction of light entering the eye to make your vision clearer. Contact lenses can also be used to assist in the healing process after cataract surgery or to treat certain eye infections and corneal injuries.
Design
Contact lenses come in several designs for specific vision disorders. Spherical and toric lenses are common and are used to treat near and far sightedness and astigmatism. Bifocal contacts are also available for multi-focal vision correction for those with presbyopia. Orthokeratology lenses are used to reshape the cornea of the eye during sleep, allowing for lens-free visual correction during the day.
Lens Wear Time
Lens wear time varies based on the material the lenses are made of. Daily wear lenses must be removed at the end of the day, then cleaned and stored. Extended wear lenses allow for wear over a longer period of time without removal, usually up to a week, even while sleeping. Continuous wear lenses can be worn without being removed for up to one month.
Fitting Contacts
Even if you have an existing prescription for glasses, you will need to see your optometrist or ophthalmologist to be measured and fitted for contact lenses because they are classified as a medical device. By law, they require proper fitting from a trained and licensed professional and are only available by prescription. During the examination, your visual correction requirements will be determined. Then you will be given your prescription. You can choose to buy your lenses from your doctor, buy them in an optical store or buy them online.
