Ophthalmologists (M.D. or D.O.) are eye surgeons who study and treat eye diseases and can also perform the duties of optometrists; optometrists (O.D.) examine eyes, diagnose and treat vision problems, and prescribe eyeglasses and contact lenses and in most states they also can prescribe medicine; opticians grind and dispense eyeglasses and in some states dispense contact lenses.

There are 75 million contact lens wearers worldwide and 31 million in the U.S. alone. Always buy from a reputable company; you can buy discount contact lenses without a prescription, but the company is selling you a prescription device as if it were an over-the-counter device, in violation of FTC regulations - selling you lenses without having a prescription from you.

The length of continuous lens wear depends on the lens type and your doctor's evaluation of your tolerance for overnight wear. Newer soft lens materials include silicone-hydrogels to provide more oxygen to your eyes. There are two general categories of contact lenses - soft and rigid gas permeable.

Rigid gas permeable lenses tend to be less expensive over the life of the lens since they last longer than soft lenses. Keep in mind contact lenses are often more complex than it appears. While the ability to hold water increases the oxygen permeability of soft lenses, it increases their fragility quotient as well.

Soft contact lenses are made of soft, flexible plastics that allow for oxygen to pass through to the cornea. 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. Rigid gas permeable contact lenses are more durable, resistant to deposit buildup, and generally give a clearer, crisper vision.

If you live an active lifestyle, NIGHT & DAY breathable lenses will allow you 30 hours of continuous wear. Rigid lenses don't absorb chemicals, unlike soft lenses which will soak up residue from your hands like soap or lotion.

Before you buy online, check to see if there are any testimonials at the online supplier's website. Check to see if you have a health insurance plan that includes vision coverage. 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.

Buy your contact lenses from a supplier you're familiar with and know is reliable or has name familiarity 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. Check out how long the online supplier has been in business before you buy.

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

When the eyes are open, tears carry adequate oxygen to the cornea to keep it healthy, but during sleep, the eye produces fewer tears, causing the cornea to swell. Basic rule: never swap your contact lenses with anyone else. Replace your contacts as recommended by your eye doctor because they wear out as time goes by.

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. 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. The use of homemade saline made by using salt tablets mixed in water is one of the biggest contributors to Acanthamoeba keratitis in contact lens wearers: the FDA no longer condones the use of salt tablets.

If you're planning to buy contact lenses, you should buy the best quality you can get, even at a higher price; you don't want to skimp on quality when it comes to your eyes. If your first lens fitting is performed by an eye care practitioner, he or she can help minimize or eliminate the cause of any eye irritation associated with the new lenses. Make sure you've done your homework before you buy any pair of contact lenses.