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Ears, Nose, Throat and Health

Contacts, hazards, advantages

What You Should Know About Contact Lenses

By Dr. W. Gifford Jones

October 27, 1996

  How should you respond when your ophthalmologist asks if you want contact lenses? More and more people are replying "Yes" to their many advantages. But it's also well to remember the sage advice of Niccolo Machiavelli. He wrote in 1513, "A man's wisdom is most conspicuous where he is able to distinguish among dangers and make choice of the least."

  No one disputes the advantages of contact lenses. They provide excellent vision and increase the size of the image in shortªsighted persons. And they decrease the amount of peripheral visual distortion.

  Contact lenses are also convenient for those engaged in sports. They don't fall off, break or steam up. And most people find them comfortable, convenient and more flattering than glasses.

  There are two types of contact lens. The rigid ones which are particularly good for patients suffering from astigmatism, (a defective curvature of the surface of the eye). It's harder for people to get used to the rigid lens, but they can be used for years.

  Soft contact lenses are now the most popular ones. Patients feel comfortable with them almost instantaneously. And for those playing sports they are not as easily displaced.

  A good number of patients choose the disposable soft lens. These can be worn for a few days to a few weeks and then replaced by a new set. Moreover, if they fall out and are lost during swimming hundreds of dollars don't go down the drain.

  Bifocal contact lenses have become available in the last few years. They are available in either the rigid or soft forms. And tinted lenses are also obtainable.

  But getting back to the wisdom of Machiavelli, there is a downside to the contact lens. The human eye blinks 20,000 times every day. This natural reaction moves a contact lens up and down over the eye, a distance equivalent to the length of three football fields!

  Good sense dictates that a foreign body in the eye moving this much every day may cause irritation. Or if left in place too long infection can occur.

  Studies reveal a tenfold increase in corneal ulceration with extended©wear soft contact lenses. Corneal ulcers are the most serious complication as they can result in visual loss. Ô 0*0*0* Corneal ulcers may be caused by debris that collects on the lens. This causes irritation of the sensitive cornea, the window of the eye. Other ulcers can be traced to faulty care of the lens and contaminated cleaning solutions.

  This is one reason disposable daily©wear soft contact lenses are increasingly popular with patients. They are comfortable, thin and particularly suited for patients who quickly accumulate deposits under the lens.

  Disposable lenses do not need special cleaning other than an overnight soak. Or storage in a disinfectant when they're not being worn.

  Ideally, contact lenses should not be worn at night. Wearing contacts with the eyes closed diminishes the amount of oxygen to the eye. It also increases the amount of deposit under the lens which further decreases oxygen to the eye.

  The best advice to contact wearers is to watch for infection. Eye infection is associated with redness, pain, blurred vision, sensitivity to light and the presence of sticky secretions. If you're not sure an infection is present use this approach,"When in doubt take them out".

  Patients who develop "red eye" should immediately consult the person who dispensed the contact lens. But if a problem lasts more than 24 hours it's mandatory that patients see an ophthalmologist.

  Dr. Mathea Allansmith of the Harvard Medical School claims that the use of contact lenses always causes a change in the ocular surface of the eye even in patients without symptoms.

  Dr Allansmith reported in 1977 a new allergic eye disease, "giant papillary conjunctivitis" (GPC). It was a rare problem at the time but has become increasingly prevalent with increased use of the contact lens.

  This disease is seen more often in people wearing soft contacts.It's believed that soft contacts attract more protein and other foreign matter than hard lenses. Allergens become imbedded in mucus©like material on the lens surface and trigger G.P.C.

  Patients with GPC complain of blurred vision, mucous discharge and a redness of the eye. By the end of the day they feel as if the lenses are drying up in their eyes and start squinting like Popeye.

  Small wonder because underneath the eyelids are clusters of small, bumps. Patients can be successfully treated by improving the lens cleaning procedure, switching to another type of lens and using sodium cromolyn to counteract the allergic reaction.

  Would Machiavelli wear contacts if he were alive today? I think in fewer than 20,000 blinks he'd opt for regular glasses.


W. Gifford-Jones M.D is the pen name of Dr. Ken Walker graduate of Harvard. Dr. Walker's website is: Docgiff.com

My book, �90 + How I Got There� can be obtained by sending $19.95 to:

Giff Holdings, 525 Balliol St, Unit # 6,Toronto, Ontario, M4S 1E1

Pre-2008 articles by Gifford Jones
Canada Free Press, CFP Editor Judi McLeod