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UV LIGHT
Ultraviolet radiation is the invisible high-energy sunlight.
It is divided into three parts UV-A, UV-B and UV-C. UV-C is
not of concern because it is filtered out by the earth’s
ozone layer. Long term exposure to UV-A and UV-B can cause
damage to the eye and lead to the development of eye
diseases including, age-related cataract, pterygium,
photokeratitis and corneal degeneration. UV light can reach
the eye directly from the sun, or from reflective surfaces
such as water, snow, and sand.
BLUE LIGHT
The high-energy visible light (HEV) from the sun comprises
the violet and blue end of the light spectrum. Long term
exposure to HEV light rays may increase the risk of
developing age-related macular degeneration (AMD). AMD, a
deterioration of the retina, is the leading cause of
blindness in people age 55 and older in the United States.
While there is not general agreement that exposure to
sunlight is a risk in acquiring AMD, there is general
agreement among experts that if sunlight is damaging to the
retina, it is the HEV—not the UV- that is most likely to
result in developing AMD.
GLARE
Glare is caused by sunlight reflected off of surfaces such
as water, roads, snow and sand. Glare can impede the ability
to view objects, wash out colors and in some instances cause
temporary blindness. (photokereatitis). It can also
intensify the exposure to harmful sunlight. Reflected glare
causes eyestrain and fatigue and can be a safety hazard for
driving and other activities.
Highly reflective surfaces
Surface
% light reflected
Snow
88%
Sea/foam/surf 27%
Dry beach sand 17%
Concrete pavement 10%
Black asphalt 7%
Wooden Boat deck 6%
(Taken from the book “See Again”
by Alexander M. Eaton, M.D.) |
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