There are more than 75 million contact lens wearers worldwide and 31 million in the U.S. alone. Be careful about buying cheap contact lenses, they may not be the quality you want; discounted quality contact lenses are the most desirable. With a contact lens prescription in hand, it's possible to buy your contact lenses from stores, the Internet, over the phone, or by mail.

Now it's easy to order the perfect contact lenses online at a great discount. 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.

Soft lenses have the added benefit in that soft lenses aren't as likely as rigid lenses to pop out or get foreign material like dust underneath. 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.

Rigid lenses don't absorb chemicals, unlike soft lenses which will soak up residue from your hands like soap or lotion. Soft contact lenses are made of soft, flexible plastics that allow for oxygen to pass through to the cornea. In some models, each lens corrects for near and distance vision and in others, one lens is for near vision, and the other is for distance.

Rigid lenses generally give you more clear vision. Extended wear contact lenses are used for overnight or continuous wear ranging from one to six nights or up to 30 days. The length of continuous lens wear depends on the lens type and your doctor's evaluation of your tolerance for overnight wear.

Rigid gas permeable lenses tend to be less expensive over the life of the lens since they last longer than soft lenses. There are several types of lenses including: soft contact lenses, rigid gas permeable lenses, extended wear lenses and disposables.

If you have an insurance plan, the insurance plan's seller's prices may or may not be better than what you can find elsewhere; this should be just one option when you're shopping for lenses. When you receive your order, if you think you've received an incorrect contact lens, check with your doctor or eye care professional right away; don't accept any substitution unless your eye care professional approves it. Check out how long the online supplier has been in business before you buy.

When you place your order make sure your lenses are available and not out of stock, because you'll need them now. Get a feel for how the retailer handles customer service calls; in case you have a problem after your order arrives. Before you buy online, check to see if there are any testimonials at the online supplier's website.

Ask about prices at your doctor's office when you have your eye examination, or during a follow-up visit after you get your prescription. Beware of attempts to substitute a brand different from the one you want when buying contacts. 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.

Be aware that extended-wear (overnight) contact lenses - rigid or soft - increase the risk of corneal ulcers, which are infection-caused eruptions on the cornea that can lead to blindness; symptoms include vision changes, eye redness, eye discomfort or pain, and excessive tearing. Always throw away disposable lenses after the recommended wearing period. Extended-wear rigid lenses can cause unexpected, undesirable, reshaping of the cornea.

Don't wear lenses any longer than they're prescribed for, nor when sleeping unless you are otherwise directed. 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. Daily-wear lenses are removed daily for cleaning and are a safer choice, provided they aren't worn during sleep.

Make sure you've done your homework before you buy any pair of contact lenses. If you're looking for cheap contact lenses, you may find that cheap materials or other ways of cutting costs will affect the quality you'll want for your precious eyes. Make sure to visit a reputable eye doctor for a complete eye examination once a year, or more frequently if needed.