A contact lens is a thin disk which floats on the surface of the eye, providing vision correction.With advances in optical technology, almost everyone now can wear contact lenses, regardless of the type or extent of their vision problems. This includes patients with astigmatism and those who need bifocal or multifocal lenses. Most practices offer a comprehensive array of contact lenses to suit their patients' individual needs. All contact lenses require a prescription.
Types of Contact Lenses
Soft Contact Lenses
Daily-wear soft contact lenses are the most popular type of contacts worn. Made of a flexible plastic polymer, daily-wear lenses are put in each morning and taken out each night. Daily-wear contacts come in many colors and typically last about one year.
Extended-wear soft contact lenses can be worn all the time, including while the patient is asleep. Depending on whether a patient has a 7-day (standard) or 30-day lenses, they only need to take out and clean their contacts once a week and to give their eyes a rest and reduce the risk of a corneal infection. Extended-wear lenses are made of soft silicone that retains moisture longer than daily-wear contacts, allows more oxygen to reach the eye and prevents bacteria and protein buildup.
Disposable soft lenses are intended to be thrown out and replaced after they have been worn for a certain period of time. This makes them even easier to maintain than regular soft contacts. Many disposable lenses are designed for either replacement every morning, every two weeks, or even every month. Daily-wear disposables are worn during waking hours only, while extended-wear disposables can be worn for longer periods.
Rigid, gas-permeable contacts offer several benefits over soft lenses. Including the following:
- Correction of a wider range of vision problems, including a high degree of astigmatism
- A sharper vision than most soft lenses
- More oxygen flow through to the eye, reducing the risk of corneal irritation
- More durable than soft lenses and don't need to be replaced as often, lasting as long as two or three years
- Less likely to tear like soft contact lenses
- Less prone to a buildup of deposit
Because they are much harder than flexible contacts, gas-permeable lenses may take some getting used to when they are first worn. They are also more likely than soft lenses to slip off the center of the eye and require adjustment, making them an inconvenient choice for patients who play sports or participate in other demanding activities. However, most patients soon grow accustomed to the feel of gas-permeable lenses and are satisfied with the improvement in vision they offer without the need for glasses.
- National Institutes of Health
- Centers for Disease Control and Prevention
- Eunice Kennedy Shriver National Institute of Child Health and Human Development
- U.S. Department of Health & Human Services
- U.S. National Library of Medicine