Printer Friendly

Ozone depletion: cause for caution, not alarm.

While studies have associated ultraviolet-B light exposure with the formation of cataracts, it will take decades to determine whether changes in the ozone layer, which predominantly blocks UV-B from the Earth's surface, will have a measurable effect on the general population. "We continue to urge the use of UB-absorbent sunglasses, but no one should be concerned that they or their children will develop cataracts overnight because they stayed out in the sun unprotected," maintains Gerald A. Fishman, a spokesman for the American Academy of Ophthalmology and an authority on sunlight and its association with eye disease. "Even if higher UV-B exposure can be demonstrated to have an effect, cataract formation will continue to occur slowly and the loss of vision will be gradual."

However, there are a number of other ocular risks associated with unprotected exposure to bright sunlight and other sources of strong UV light. As with cataracts, most greatly are reduced by wearing proper protection.

* Burns. Excessive exposure to ultraviolet light without protective eye wear can cause a sudden, temporary, and painful burn to the surface of the eye. Ultraviolet-induced keratoconjunctivitis, sometimes called snow blindness, often is observed a few hours after skiing, sunbathing, or arc welding. The burn results in severe pain and often a temporary inability to open the eyes comfortably.

* Chronic UV exposure may contribute to an abnormal growth on the surface of the eyeball called a pterygium. It most often is encountered among farmers and other outdoor laborers, especially in the Sunbelt states. A pterygium can grow over the cornea, partially blocking vision. Surgery to remove it usually is recommended if sight appears threatened.

* Visible light usually is not damaging to the eye. A flash of bright light merely will bleach pigments temporarily, causing spots in the visual field. However, staring directly at the sun, a source of intense visible light, will burn--and permanently scar--the retina. UV-absorbent sunglasses can not protect the eye from damage caused by staring at the sun.

* Photosensitizing chemicals can make the eyes especially sensitive to sunlight. These include psoralen compounds, used to treat psoriasis, and certain antibiotics, such as tetracycline and sulfa drugs.
COPYRIGHT 1993 Society for the Advancement of Education
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1993 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Publication:USA Today (Magazine)
Date:Feb 1, 1993
Words:354
Previous Article:Can nerve cells regenerate?
Next Article:Testing for deadly bacteria.
Topics:


Related Articles
Ozone reports stir debate.
Ozone hole hikes Antarctic ultraviolet.
UV pours through ozone hole.
Incomplete data on ozone layer harming crops.
Shades of summer.
UV rays strengthening in North America.
Ozone alert; frogs, plankton and people show effects of ozone depletion.
Cover-up bid by scientists.
Ozone Depletion & Global Warming.
Ozone layer depletion will lead to increase cases of skin cancer, cataracts.

Terms of use | Copyright © 2016 Farlex, Inc. | Feedback | For webmasters