Contact lenses fit snugly in the eye to correct vision without the need for wearing traditional glasses. The original concept for lenses was first proposed by Leonardo da Vinci in the early 1500s. It took approximately 270 years to design a contact lens that was practical for daily use.
Hard Lenses
The first hard contact lenses were made of glass, but today they consist entirely of plastic. The most commonly prescribed hard lenses are rigid and gas permeable lenses, or RGP lenses. Their rigid structure allows for a custom fit and crisper vision. They are durable, but they easily absorb soap and lotion from the fingers during handling. To keep these long-lasting lenses free of protein and lipids, a strict cleaning schedule must be maintained.
Soft Lenses
Soft contact lenses are flexible and easily absorb water. Their higher concentration of water, up to 80 percent, allows users to wear them for extended periods of time. Soft contact lens wearers can freely switch between contact lens use and their glasses for vision correction. Disposable soft contacts are available, reducing the need for strict cleaning and maintenance schedules.
Choosing the Right Lens
Comfort is one factor in choosing a contact lens. The newer RGP lenses allow oxygen to permeate and are quite comfortable after a short adjustment period. Soft contacts do not require an adjustment period or strict maintenance, but may not offer the crispness of vision desired. An optometrist is specially trained to evaluate patients vision needs and to prescribe the right lens.
