Prevention of Blindness Society...
MACULAR DEGENERATION
NETWORK NEWS
MARCH 2001
Sunglasses Are Not Just For Summer
At
the Virginia Aging Eye Network meeting on February 15th, Dr. Jeet Athelli
provided valuable information on sunglasses and the protection they provide for
eyes. He emphasized that
prolonged exposure to the sun's rays can increase chances of developing macular
degeneration (AMD); accelerate cataracts; cause cancer of the eyelid and skin
around the eye; benign growths on the eye's surface; and a painful but
temporary sunburn of the eye's surface. People of all ages and ethnic
backgrounds should protect their eyes from the sun.
Dr. Athelli discussed the three different types of
ultraviolet radiation—UV-A, UV-B, and UV-C. UV-C is absorbed by the ozone layer and does not present any
threat. Long-term exposure to UV-A
and UV-B can lead to damage to the eye.
To truly protect your eyes, look for sunglasses with“99% or 100% UV-A
and UV-B protection” or “protection to 400 nm’s.” More than 33% of sunglasses claim to have UV protection, but
do not have the protection you need to protect your eyes. Price does not buy appropriate UV
protection, so the more expensive pairs do not guarantee more benefits for your
eyes.
In addition to the right sunglasses, the brim of a
hat or the sun visor in your car can also block out 50 percent of the UV
exposure to your eyes. Sun can
creep in above your sunglasses and still do damage. A UV coating can be added
to your regular glasses to help protect eyes.
Reducing brightness can give you more comfortable
vision. It is recommended that you
screen out 75-90 percent of visible light. If you can easily see your eyes through your sunglasses,
then they probably are not dark enough to screen out the right amount of
sun. People with low vision will
have difficulty seeing if the sunglasses are too dark. It is important to find the right
shading.
Polarized sunglasses help guard against glare. Reflected glare, such as water, snow,
ice, can make driving a car or boat difficult. Internal glare from cataracts can also effect vision. An
anti-reflective coating can be added to glasses to help reduce glare from the
back surface of the lenses.
Different shades of lenses are best for individual
situations:
·
Gray is best used to decrease brightness and
provides even color contrasts.
·
Brown is used to increase color contrast and cut
down on brightness. Useful for
sports, such as golf.
·
Green offers a mild color contrast and decreases
brightness.
·
Yellow does not decrease brightness, but increases
contrast.
·
Blue is not recommended since it interferes with
color perception, which is especially harmful while driving (traffic lights).
There
are several terms to be aware of when buying the best sunglasses for yourself. Photochromic
lenses darken or lighten with the amount of light available. They work for many, but some people
find that they do not always work in the car because they do not darken as much
in the car. They are also
temperature sensitive, so they may get darkest on a cold day and not as dark on
a hot day.
Plastic
lenses tint easily and the amount of tint can be adjusted, but polycarbonate
lenses provide the most impact resistance. Polycarbonate lenses are preferable if you participate in
potentially eye hazardous work or sports.
Wrap-around
sunglasses, shaped to keep light from shining around the frames, can be worth
considering, particularly if you spend a lot of time outdoors in bright
sunlight. Studies have shown that enough UV rays enter under, over and around
the sides of ordinary frames to significantly reduce the benefits of protective
lenses. Large-framed,
close-fitting wraparound sunglasses protect your eyes from all angles.
The Prevention of Blindness Society sells complete
UV and glare protection sunglasses - - 100% UV protection to 400 nm’s - - in
several different colors. For more
on the Society’s sunglasses or for a free brochure on “Sunglasses,” call (202)
234-1010.
© 2001
Prevention of Blindness Society of the Metropolitan Area, Washington, DC. All
Rights Reserved.