Contact lenses, just like glasses, correct nearsightedness, farsightedness, and astigmatism. Of the nearly 11 million Americans with refractive errors, nearly 20 percent wear contacts. While some people prefer the look of glasses, others utilize contact lenses.
While contacts have been around for many years, it wasn’t until 1979 that extended wear contacts appeared on the scene. There are two types of lenses are classified by wearing time:
Daily wear — must be removed nightly
Extended wear — can be worn overnight, usually for seven days consecutively without removal
We don’t necessarily recommend extended wear contacts. While they are safe, we believe that you should give your eyes a break when possible.
Contacts are classified not only by the wear time, but the material. There are three types of contact lenses:
- Soft lenses are made from gel-like, water-containing plastics called hydrogels, and cover the entire cornea.
- GP lenses, also known as RGP or "oxygen permeable" lenses, are made from rigid, waterless plastics and are especially good for presbyopia and high astigmatism. GP lenses are smaller in diameter and often provide sharper vision than soft lenses.
- Hard lenses are made from a rigid plastic material called PMMA that does not transmit oxygen to the eye. These lenses have virtually been replaced by GP lenses and are rarely prescribed today.
Soft lenses have four different classifications based on the disposal timeline.
Daily disposable lenses — Discard after a single day of wear
Disposable lenses — Discard every two weeks, or sooner
Frequent replacement lenses — Discard monthly or quarterly
Traditional (reusable) lenses — Discard every six months or longer
These are just a few basic things to know about contacts, however if you are interested in trying contacts for the first time, please make an appointment with Dr.Ephraim.