In the U.S. contact lens marketplace, 82 percent wear soft lenses, 16 percent wear rigid gas-permeable, and only 2 percent wear hard. The choice of which lens is right for you should be based only on an examination by your doctor or eye care professional, not over the phone.

Although easier to handle and less likely to tear, rigid gas permeable lenses are not as comfortable initially as soft contacts and it may take a few weeks to get used to wearing the RGPs, compared to just a few days for soft contacts. While the ability to hold water increases the oxygen permeability of soft lenses, it increases their fragility quotient as well. The expiration date for your prescription is currently set by your state requiring a one-year or two-year renewal; if your state hasn't set a minimum expiration date, government regulation sets a one-year date unless your eye doctor determines there's a medical reason for less than one year.

Rigid lenses generally give you more clear vision. The length of continuous lens wear depends on the lens type and your doctor's evaluation of your tolerance for overnight wear. It's important for your eyes to have a rest, without lenses, for at least one night following each scheduled removal.

There are several types of lenses including: soft contact lenses, rigid gas permeable lenses, extended wear lenses and disposables. Newer soft lens materials include silicone-hydrogels to provide more oxygen to your eyes. Soft lenses are easier to adjust and are much more comfortable than rigid lenses, because they conform to the eye and absorb and hold water.

Bifocal correction is possible with both soft and rigid lenses. If you live an active lifestyle, NIGHT & DAY breathable lenses will allow you 30 hours of continuous wear.

You can buy contact lenses from an eye doctor, on the Internet, from an optical store or a warehouse club. Rebates may be available from the seller, from the manufacturer, for first-time contact lens wearers and for individuals who buy lenses and get an eye exam. Before you buy online, check to see if there are any testimonials at the online supplier's website.

Beware of attempts to substitute a brand different from the one you want when buying contacts. When you place your order make sure your lenses are available and not out of stock, because you'll need them now. Make sure you have a current, valid prescription when you order contact lenses.

Always ask what rebates are available. When you place your contact lens order, request the manufacturer's written patient information for your contact lenses; it'll give you important risk and benefit information as well as instructions for use. Get a feel for how the retailer handles customer service calls; in case you have a problem after your order arrives.

Soft extended-wear lenses bind down on the closed eye, but they are porous and allow some tears through during sleep; because they have so little form, their binding has very little effect on the shape of the eye. One sight-threatening concern is the infection Acanthamoeba keratitis, which is caused by improper lens care; this difficult-to-treat parasitic infection's symptoms are similar to those of corneal ulcers.

To be sure your eyes remain healthy you shouldn't order lenses with a prescription that's expired or stock up on lenses right before the prescription is about to expire; it's much safer to be re-checked by your eye doctor.

Microorganisms may be present in distilled water, so always use commercial sterile saline solutions, if you plan to use enzyme tablets in water for disinfection. Heat disinfection is the only method effective against the microroganism Acanthamoeba keratitis, a common culprit for contact lens wearers, and it also kills organisms in and on the lens case. Daily-wear lenses are removed daily for cleaning and are a safer choice, provided they aren't worn during sleep.

Remember to use only contact lenses that are FDA-approved and only if prescribed by a licensed eye care professional. Laser surgery and its risks can be frightening and too expensive for some people; contacts can provide a safe, comfortable and time-tested alternative. No matter which lenses your doctor prescribes, be sure to ask for written instructions and follow them carefully.