2007年12月18日星期二

Nurses Guide To Contact Lenses - Facts And Safety

Among the many kinds of contact lenses you can buy are: novelty, colored, crazy, Halloween, special effects, theatrical, costume, scary, glow in the dark, wild eyes, mirrored, black, white, and red. Before you buy contact lenses from anyone other than your eye care professional, it pays to be a wise consumer. All correcting contact lenses must have a valid prescription from an ophthalmologist or optometrist.

You'll want to take simple precautions to make any lens purchase safe and effective. 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.

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

While the ability to hold water increases the oxygen permeability of soft lenses, it increases their fragility quotient as well. Newer soft lens materials include silicone-hydrogels to provide more oxygen to your eyes. There are also a few rigid gas permeable lenses that are designed and approved for overnight wear.

People who have good distance vision but need help for reading can get a monovision reading lens for one eye. Bifocal correction is possible with both soft and rigid lenses. Contacts provide for excellent peripheral vision for sports, driving, safety, and performing.

Keep in mind that contact lenses are often more complex than usually thought. Disposable lenses don't come with instructions for cleaning and disinfecting, while those labeled specifically for planned replacement do.

Always ask what rebates are available. Always buy from a reputable company; you can buy contact lenses without a prescription, but the company is selling you a prescription device as if it were an over-the-counter device violating FTC regulations by selling you contact lenses without having your prescription. 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. When you place your order make sure your lenses are available and not out of stock, because you'll need them now. 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.

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. Carefully check to make sure the company gives you the exact brand you ordered, the name of the lens, the power, sphere, cylinder, if any, axis, if any, diameter base curve, and peripheral curves, if any. 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.

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. The FDA has approved extended-wear lenses for use up to seven days before removal for cleaning; but there are risks with use of extended-wear lenses even for one night. Replace your contacts as recommended by your eye doctor because they wear out as time goes by.

Heat disinfection is the only method effective against the microorganism Acanthamoeba keratitis, a common culprit for contact lens wearers, and it also kills organisms in and on the lens case. Extended-wear rigid lenses can cause unexpected, undesirable, reshaping of the cornea. 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. 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. Shopping for contacts online will save you a lot of money; contact lenses are deeply discounted.