Contact Lenses


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by Dixie Farley

Modified by FAQS.ORG

Imagine wearing your contact lenses for a few hours and then, after you pop them out, still seeing clearly for a portion of the day. For certain individuals with nearsightedness, that image can be reality, thanks to a new lens the Food and Drug Administration recently cleared for marketing.

The OK rigid gas-permeable contact lens, made by ConTEX, Sherman Oaks, Calif., is the first lens designed to correct nearsightedness by temporarily reshaping the transparent tissue known as the cornea that covers the iris and pupil. It is just one of many choices for the 28 million Americans who wear contact lenses.

These medical devices, sold under more than 350 brand names, offer numerous options, including rigid-lens handling ease, soft-lens comfort, bifocal vision, a rainbow of colors, no-fuss disposables, and even protective help against ultraviolet radiation.

Shaping Up

The idea behind the OK lens is not new. Since the early 1960s, some optometrists have used conventional daily-wear rigid lenses to reshape corneas. This procedure is called orthokeratology, or Ortho-K. FDA considers such treatment of an individual patient to be the practice of medicine and therefore not subject to regulation. Selling contacts not cleared for Ortho-K to practitioners for this use is illegal marketing, however, so the agency is helping manufacturers obtain clearances specifically for Ortho-K. 

Studies before FDA began regulating contact lenses, in 1976, show that Ortho-K appears to be safe, says James Saviola, O.D., chief of the vitreoretinal and extraocular devices branch at FDA's Center for Devices and Radiological Health. "The lower your amount of nearsightedness, the greater your probability of success with Ortho-K," he says.

Ortho-K reshaping involves the use of a series of lenses that apply pressure to the cornea. Once the desired result is achieved, use of daily-wear maintenance lenses is crucial to retain the reshaping. If you wear the maintenance lenses faithfully, Saviola says, "you may only need to wear the lenses for a portion of the day."

However, Ortho-K does not work for everyone. Some people do not experience any significant reduction in nearsightedness. "An individual's response is difficult to predict," Saviola says. "It may take weeks or months to have an effect."

Safety Concerns

The most serious safety concern with any contact lens is related to overnight use. Extended-wear (overnight) contact lenses--rigid or soft--increase the risk of corneal ulcers, infection-caused eruptions on the cornea that can lead to blindness. Symptoms include vision changes, eye redness, eye discomfort or pain, and excessive tearing.

The risk of corneal ulcers for people who keep extended-wear lenses in overnight is 10 to 15 times greater than for those who use daily-wear lenses only while awake, says James Saviola, O.D., chief of the vitreoretinal and extraocular devices branch at FDA's Center for Devices and Radiological Health.

When the eyes are open, he explains, tears carry adequate oxygen to the cornea to keep it healthy. But during sleep, the eye produces fewer tears, causing the cornea to swell. Under the binding down of a rigid contact lens during sleep, the flow of tears and oxygen to the cornea is further reduced. This lack of oxygen leaves the eye vulnerable to infection.

Extended-wear rigid lenses also can cause unexpected, sometimes undesirable, reshaping of the cornea.

Soft extended-wear lenses also 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 little effect on the shape of the eye.

FDA has approved extended-wear lenses for use up to seven days before removal for cleaning. Still, there are risks with use of extended-wear lenses, "even if it's just one night," Saviola says. Daily-wear lenses are removed daily for cleaning and are a safer choice, provided they aren't worn during sleep.

Another sight-threatening concern is the infection Acanthamoeba keratitis, caused by improper lens care. This difficult-to-treat parasitic infection's symptoms are similar to those of corneal ulcers.

The use of homemade saline from salt tablets is one of the biggest contributors to Acanthamoeba keratitis in contact lens wearers. "FDA no longer condones the use of salt tablets, and neither should a concerned pharmacist," writes Janet Engle, Pharm.D., in the 1996 Handbook of Nonprescription Drugs. Engle is associate dean for academic affairs and clinical associate professor of pharmacy practice at the University of Illinois in Chicago.

Microorganisms may also be present in distilled water, so always use commercial sterile saline solutions to dissolve enzyme tablets. Heat disinfection is the only method effective against Acanthamoeba, and it also kills organisms in and on the lens case. 

The Options

82 percent wear soft lenses, 2 percent wear hard, and 16 percent wear rigid gas-permeable. Soft lenses are much more comfortable than rigid lenses, thanks to their ability to conform to the eye and absorb and hold water. You can get used to soft lenses within days, compared with several weeks for rigid. An added benefit is that soft lenses aren't as likely as rigid lenses to pop out or capture foreign material like dust underneath. Extra-thin soft lenses are available for very sensitive people.

While the ability to hold water increases oxygen permeability of soft lenses, it increases their fragility as well.

Rigid lenses generally give clearer vision. They can be marked to show which lens is for which eye. They don't rip or tear, so they're easy to handle.

Also, rigid lenses don't absorb chemicals, unlike soft lenses, which Saviola says are like sponges. "They'll suck up any residues on your hands--soap, lotion, whatever."

Both soft and rigid lenses offer bifocal correction. In some models, each lens corrects for near and distance vision. In others, one lens is for near vision, and the other is for distance. Middle-aged people who have good distance vision but need help for reading can get a monovision reading lens for one eye.

Soft lenses additionally come as disposable products (defined by FDA as used once and discarded) or as planned-replacement lenses.

With planned-replacement lenses, the practitioner works out a replacement schedule tailored to each patient's needs, says Byron Tart, director of promotion and advertising policy at FDA's devices center. "For patients who produce a higher level of protein in their eyes or don't take as good care of their lenses, it might be healthier to replace the lenses more frequently," he says.

Some practitioners prescribe disposables as planned-replacement lenses, which are removed, disinfected and reused before being discarded. Saviola cautions that lenses labeled "disposable" don't come with instructions for cleaning and disinfecting, while those labeled specifically for planned replacement do. Whatever lenses your practitioner prescribes, be sure to ask for written instructions and follow them carefully.

Very few people wear hard lenses, but they are available for people who have adapted to them and want them. Hard lenses are not the same as rigid gas-permeable lenses, since they do not allow oxygen transmission through the lens.

Contacts Not for Everyone

People with inadequate tearing (dry eye syndrome) usually can't tolerate contacts, says Donna Lochner, chief of the intraocular and corneal implants branch of FDA's devices center. In addition, Lochner says, "Severe nearsightedness often can't be corrected effectively with contact lenses."

Saviola notes that certain working conditions, such as exposure to chemical fumes, may be undesirable for contact-lens wearers. Contacts may be ruled out by allergy to lens-care products or by corneal problems, such as a history of viral infection of the cornea. "Extra caution," he says, "should be exercised with diabetics, because they're susceptible to infection and have trouble healing."

Cosmetic use of contacts is limited in children. Adolescence is the youngest age as a rule to consider contact lenses, says Saviola, but some practitioners do fit 9- to 11-year-olds. "You may prescribe for a younger child who has the motor skills and responsibility to handle contact lenses."

For some people who haven't been able to wear contacts and want to, implantable lenses may be an option in the future.

Doctors are studying ring segments, "shaped like parentheses," Lochner says, which are implanted in the cornea. "They flatten out the cornea, changing the shape to give the correct optical power." Lenses that are implanted inside the eye are also being studied to correct refractive error, she says.

Correcting vision is not the only use for contact lenses.

Some soft contacts are used as bandage lenses after photorefractive keratectomy laser surgery for nearsightedness. The surgery removes the outer cell layer of the cornea, creating a large abrasion on the eye. "It's excruciatingly painful," Saviola says, "if you don't have a protective covering on the cornea after the anesthetic wears off."

Collagen eye shields are used as bandage lenses to relieve pain from other abrasions or sores on the cornea. They dissolve in a couple of days.

Comparison Shopping

Companies that sell contact lenses compete stiffly for business, offering discounts and premiums such as a second set free.

But a discount for the lenses might not save you money if the price doesn't include other needed products and services, such as a thorough eye examination, lens-care kit, and follow-up visits to make sure you're adapting. A moderate cost for a package that has everything you need may be the best deal.

Before you make an appointment, ask the practitioner these questions:

  • Will you give me my prescription? (You may want the prescription if you decide to go to another practitioner or order lenses from an alternate source.)
  • What tests are included in the eye examination?
  • What do you charge for the examination, lenses, evaluation, fitting, lens-care kit, follow-up visits, and service agreements?
  • What is your refund policy if I can't adapt to contact lenses?
  • How many types and brands of contact lenses do you sell?
  • How much do you charge for replacement lenses?

Asking questions about any new prescription treatment is always a good idea. Like medicines, contact lenses provide benefits and pose risks. But even with the increased risk of corneal ulcers posed by extended-wear lenses, Saviola says this risk alone isn't enough to say the devices aren't safe and effective if properly used.

"If people are informed," he says, "then they're making a judgment based on available information. That's the thing we always struggle with, conveying enough information to people and having the practitioner convey enough information, so that the consumer can make an informed choice."

Dixie Farley, who was on the staff of FDA Consumer for more than 13 years, retired from federal service in January.


Proper Care Gives Safer Wear

chart illustrating proper lens care
  • Follow, and save, the directions that come with your lenses. If you didn't get a patient information booklet about your lenses, request it from your eye-care practitioner.
  • Use only the types of lens-care enzyme cleaners and saline solutions your practitioner okays.
  • Be exact in following the directions that come with each lens-care product. If you have questions, ask your practitioner or pharmacist.
  • Wash and rinse your hands before handling lenses. Fragrance-free soap is best.
  • Clean, rinse and disinfect reusable lenses each time they're removed, even if this is several times a day.
  • Clean, rinse and disinfect again if storage lasts longer than allowed by your disinfecting solution.
  • Clean, rinse and air-dry the lens case each time you remove the lenses. Then put in fresh solution. Replace the case every six months.
  • Get your practitioner's okay before taking medicines or using topical eye products, even those you buy without a prescription.
  • Remove your lenses and call your practitioner right away if you have vision changes, redness of the eye, eye discomfort or pain, or excessive tearing.
  • Visit your practitioner every six months (more often if needed) to catch possible problems early.

Watch Out:

  • Never use saliva to wet your lenses.
  • Never use tap water, distilled water, or saline solution made at home with salt tablets for any part of your lens care. Use only commercial sterile saline solution.
  • Never mix different brands of cleaner or solution.
  • Never change your lens-care regimen or products without your practitioner's okay.
  • Never let cosmetic lotions, creams or sprays touch your lenses.
  • Never wear lenses when swimming or in a hot tub.
  • Never wear daily-wear lenses during sleep, not even a nap.
  • Never wear your lenses longer than prescribed by your eye-care practitioner.



Buyer Beware

Sorting help from hype in any media--the World Wide Web, television, or print--can pose a problem. So remember: If a claim sounds too good to be true, it probably is.

Here are some recent examples of potential problems:

  • Special effects contacts promoted on the Web with names like "Vampire" and "Reptilian" may sound fun to try, but they could be risky, says FDA's James Saviola, O.D. "We currently have no information that shows pigments in these lenses are safe in the eye." While FDA hasn't been strict about similar lenses used on a very limited basis by entertainers, Internet advertising takes them beyond isolated theatrical usage.

  • Buying mail-order contacts with no prescription calls for caution, says Saviola. "If your current lens has a 14-millimeter (mm) diameter and 8.7 base curve, and the mail-order company switches to another brand lens with a 14.0-mm diameter and 8.8 curve, it seems like it's about the same size and shape and should fit well. Maybe it will. But the new brand is a different material. It may leave your eyes uncomfortable."

  • A misleading print ad for Acuvue contacts was corrected last year after an FDA warning. The ad showed a man and woman half indoors and half outdoors on a sunny beach--no protective eyewear. "Open your eyes to the UV around you," it stated. "And you'll be glad Acuvue contact lenses are introducing UV protection." Writing to Vistakon Inc., of Johnson & Johnson Vision Products Inc., FDA warned: "The combination of this picture and the accompanying language implies that wearing the Acuvue UV-absorbing lens outside offers as much protection as one would naturally have indoors." Warnings in tiny print that the lenses were not substitutes for UV-absorbing eyewear did not "counteract the overall message" that the lenses provided full UV protection, the agency wrote. The company also corrected a similar TV ad.

  • Misleading pricing a few years earlier prompted consumer lawsuits against Bausch & Lomb for selling the same lens under three different names, at three different prices.

  • Charges of false claims were settled by the Federal Trade Commission last November against J. Mason Hurt, O.D., of Bartlett, Tenn. Hurt had touted his Precise Corneal Molding orthokeratology treatment as a permanent cure for defective vision. A consent agreement prohibits Hurt from making further false claims and requires reliable scientific evidence for future claims.




At a Glance

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. In most states, they also can prescribe medicine.

Opticians grind and dispense eyeglasses and in some states dispense contact lenses.