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Contact Lens |
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Contact lenses are being increasingly used. There are different types of contact lenses which are more healthful and convenient compared to a few years ago. Contact lenses can also provide a full field of unobstructed vision, which is good for participation in sports. Contact lenses have been around for more than 100 years. New developments in contact lens technology have been made in recent years that allow just about everyone to wear contact lenses. If you're new to contact lenses, your first step is to see an eye doctor. They must be prescribed and properly fitted by an eye care professional. He/she will evaluate your visual needs, your eye structure, and your tears to help determine the best type of lens for you.
The many types of contact lenses currently available
Hard lenses are made from PMMA. These lenses are virtually obsolete and rarely used.
Soft lenses are made from gel-like, water-containing plastics, and are most common. They're a bit larger in size than your iris (the colored part of your eye). They are made of Hydrogel plastics and Silicon hydrogel.
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. These lenses are usually about eight millimeters in diameter, which is smaller than your iris..
Based on the duration of wear, they can be of two types
- Daily wear — must be removed nightly
- Extended wear — can be worn overnight, usually for seven days consecutively without removal
"Continuous wear" is a type of extended wear lens that can be worn for 30 consecutive nights.
Many lens designs are available to correct various types of vision problems:
- Spherical contact lenses are the typical, rounded design of contact lenses, which can correct myopia (nearsightedness) or hyperopia (farsightedness).
- Bifocal contact lenses contain different zones for near and far vision to correct presbyopia, which is the age-related, decreased ability to obtain a full range of vision.
- Toric contact lenses correct for astigmatism, as well as for myopia and hyperopia.
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Contact Lens Wear and Care
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Caring for your contact lenses, cleaning, disinfecting and storing them, is very important and is much easier than it used to be. A few years ago, you would have needed several bottles of cleaning products, and perhaps enzyme tablets, for proper care. Today, most people can use "multipurpose" solutions, meaning that one product both cleans and disinfects, and is used for storage. Some people who are sensitive to the preservatives in multipurpose solutions might need preservative-free systems, such as those containing hydrogen peroxide. Of course, you can avoid lens care altogether by using daily disposables.
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Contact Lens Problems
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People react differently to various lens materials and cleaning solutions. Also, the correct "parameters" of your lens — that is, power, diameter, and curvature — can be finalized only after you've successfully worn the lens. This is especially true for more complex fits involving extra parameters, such as with bifocals or toric contact lenses for astigmatism.
If you experience discomfort or poor vision when wearing contact lenses, chances are that an adjustment or change of lens can help. Today, more contact lens choices than ever are available to provide comfort, good vision, and healthy eyes. If you're not feeling good and seeing well, see consultation with your eye doctor. |
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