Sight & Hearing

May 2002

Summer Eye Safety

May is National Sight-Saving Month
In time for hitting the beach this summer, here are some often-asked questions about the sun’s effects on the eye and the American Academy of Ophthalmology’s tips for selecting proper eye protection.

How does sunlight damage the eye?
The sun emits two types of ultraviolet (UV) radiation UV-A and UV-B that are harmful not only to your skin but to your eyes. Excessive exposure to UV, especially from light reflected off sand, snow or pavement, can produce a burn on the surface of the eye. Like a sunburn on the skin, eye surface burns are painful but usually temporary. Long-term exposure to ultraviolet (UV) rays has been linked to a host of eye diseases, including macular degeneration; cataracts, or clouding of the lens; intraocular malignant melanoma (eye cancer); pterygium (tissue growth over the cornea); and photokeratitis (snow blindness).

Who is most at risk for eye damage by UV light?
A person’s lifestyle appears to be the most important factor in determining who will be most affected. Those who spend considerable time in the sun or those who live at high elevations or near the equator, where UV levels are increased, are at the greatest risk. Medical circumstances also can predispose a person to eye damage from UV. People taking photosensitizing drugs can be more sensitive to light, as well as patients who have had cataract surgery.

How can you protect your eyes from UV damage?
You can greatly reduce your eyes’ exposure by donning sunglasses and a wide-brimmed hat.

Shopping tips when purchasing sunglasses
The American Academy of Ophthalmology suggests the following guidelines when shopping for sunglasses:

UV-Absorption:
Check for a manufacturer’s label indicating whether the sunglasses are UV-absorbent or if they meet the American National Standards Institute’s guidelines for eye wear. Glasses that block 99-100 percent of UV (both UV-A and UV-B) light are recommended. Wrap-around or close-fitting UV-absorbent sunglasses offer the most protection. Glasses that do not fit close to the fact tend to allow light to penetrate the eyes by seeping in around the lenses.

Lens Color:
The color of the lens and the darkness of the tint are not good indicators of the glasses’ ability to filter out UV light. Lens color should cause as little color distortion as possible. Dark gray or dark green tints permit the most normal color vision.

Price:
The price of a pair of sunglasses is no indication of their ability to absorb UV light. Many $10 glasses provide protection equal to or greater than a $100 pair.

Polarized Lenses:
This type of lens tends to reduce reflection and glare and is especially effective around water and snow.

Photochromic:
Photochromic lenses change color in response to sunlight, often preventing the need for two pairs of prescription glasses. These lenses, however, may not change quick enough to accommodate comfortable transitions between indoor light and bright outdoor light.

Special Coatings:
Clear UV-absorbing coatings are available for everyday glasses. The coating is often applied to glasses used for skiing, high-altitude flying and other outdoor sports.

Lens Material:
The Food and Drug Administration requires that all eyeglass lenses, including those for sunglasses, be made of impact-resistant glass or plastic. This does not mean that the lenses are shatterproof but that they can withstand moderately sharp blows.