Contact lenses have been around for more than a hundred years. During that time, many advancements have allowed just about everyone to wear contact lenses. If you were told in the past that you couldn't wear contact lenses, odds are that's not true today. There are more convenient and healthy contact lens options than ever.
The many types of contact lenses currently available can be grouped in various ways:
Contact Lens Materials
Classified by material, there are three types of contact lenses:
•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.
•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 These lenses have virtually been replaced by GP lenses and are rarely prescribed today.
Contact Lens Wearing Time
Daily wear contact lenses must be removed before sleeping. Extended wear lenses can be worn overnight, usually for seven days consecutively without removal.
Disposal Intervals for Contact Lenses
Even with proper care, contact lenses (especially soft contacts) should be replaced frequently to prevent the build-up of lens deposits and contamination that increase the risk of eye infections.
Soft lenses have these general classifications, based on how frequently they should be discarded:
•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
Gas permeable contact lenses are more resistant to lens deposits and don't need to be discarded as frequently as soft lenses. Often, GP lenses can last a year or longer before they need to be replaced.
Contact Lens Designs
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.
•Orthokeratology lenses are specially designed to reshape the cornea during sleep, providing lens-free daytime wear.
•Toric contact lenses correct for astigmatism, as well as for myopia and hyperopia.
All of these lenses can be custom made for hard-to-fit eyes. Many other additional lens designs are available. Typically these are less common and fabricated for use in special situations, such as correcting for keratoconus.
More Contact Lens Features
Contacts for Dry Eyes. Certain soft contact lenses are specially made to reduce the risk of contact lens-related dry eye symptoms.
Colored Lenses. Many of the types of lenses described above also come in colors that can enhance the natural color of your eyes — that is, make your green eyes even greener, for example. Other colored lenses can totally change the color of your eyes, as in from brown to blue.
Special-Effect Lenses. Also called theatrical, novelty, or costume lenses, special-effect contacts take coloration one step further to make you look like a cat, a vampire, or another alter-ego of your choice.
Prosthetic Lenses. Opaque soft lenses called can be custom-designed for an eye that has been disfigured by injury or disease to mask the disfigurement and match the appearance of the other, unaffected eye.
Custom Lenses. If conventional contact lenses don't seem to work for you, you might be a candidate for custom contact lenses that are made-to-order for your individual eye shape and visual needs.
UV-Inhibiting Lenses. Some soft contact lenses help protect your eyes from the sun's ultraviolet rays that can cause cataracts and other eye problems. But because contacts don't cover your entire eye, you still should wear UV-blocking sunglasses outdoors for the best protection from the sun.
Hybrid Lenses. One brand of lenses features a GP center with a soft outer skirt, providing wearers with both the crisp optics of a rigid lens and the comfort of a larger, soft lens.
Scleral Lenses. Large-diameter gas permeable lenses called scleral contacts are specially designed to treat keratoconus and other corneal irregularities, as well as presbyopia.
Which Contact Lens Is Right for You?
Your eye care practitioner is skilled in evaluating your eye's physiology, and your eyesight, to determine which lens will best fit your eyes and correct your vision.
You may also consider your "wish list" of contact lens features — colors, for example, or overnight wear.
Contact Lens Wear and Care
Caring for your contact lenses — cleaning, disinfecting and storing them — 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 wearing daily disposable contact lenses.
Today, more contact lens choices than ever are available to provide comfort, good vision, and healthy eyes. If your eyes or lenses are uncomfortable or you are not seeing well, remove your lenses and visit your eye care professional to explore your options for more comfortable contact lens wear.
Article ©2011 Access Media Group, LLC.