Winter Eye
Protection
Sun protection
for the eyes may be more important during the winter months, although most
people associate it with summertime. If you live in, or are visiting
a winter climate, you are likely to to be at increased risk for
significant and dangerous glare while driving. If you participate in
wintertime outdoor sports, you may be at risk for "snow blindness", which
can be painful and temporarily impairing to the vision. Using
appropriate sunglasses or goggles may virtually eliminate those risks.
During winter months, the sun sits lower in the sky and at a different
angle, which can expose people to more ultraviolet light and glare.
These risks may be just a significant on gray, overcast winter days as
during clear days. Spending long periods of time outdoors increases
the risk. Just because the sun is not as intense or hot as it is
during the summer does not mean that a person does not need protection.
The people at the highest risk for sun related problems include children,
outdoor workers, and snow sports enthusiasts because they tend to spend
longer hours out doors, and often in conditions that create the most
exposure to ultraviolet light.
Some facts about the effect of ultraviolet light on the eye include:
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Ocular tissues are more vulnerable to ultraviolet light induced
damage than the skin.
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Age-related cataract, age-related macular degeneration, pterygium,
photokeratitis ("flashburn"), and cancer of the eyelids and skin around
the eyes are examples of sunlight-related eye diseases.
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The highest ultraviolet exposure occurs during light overcast
conditions where the horizon is visible and ground surface reflection is
high (such as snow covered conditions).
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In snowy conditions, ultraviolet rays are reflected upward, hitting
you from above and below. Up to 85% of ultraviolet rays may be
reflected up into your eyes.
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Ultraviolet is more damaging at higher altitudes because the ari
filters out about 4% less radiation for every 1,000 feet above sea
level. At 5,000 feet, a typical elevation for U.S. ski resorts,
you are exposed to 20% more ultraviolet radiation.
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Exposure to ultraviolet in childhood may be more damaging than
exposure in adulthood.
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Outdoor workers frequently are exposed to ultraviolet levels that
are above the current safe exposure limits.
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The risk of all sunlight-related eye diseases can be diminished by
use of eye wear that absorbs ultraviolet radiation during exposure to
sunlight.
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Anti-reflective coatings and polarizing filters help to decrease
glare, but polarization alone does not block ultraviolet light.
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Ultraviolet coatings on contact lenses are important, but do not fully
protect the eyes. Contact lens wearers should additionally wear
sunglasses.
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Certain drugs may make the eyes more sensitive to light. Be
sure to read drug labels and take appropriate precautions.
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Children's eyes need to be protected, as they are more prone to sun
damage because their natural lenses are clearer.
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Wearing sunscreen on the face and around the eyes adds another layer
of protection against ultraviolet light.
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It is important to never look directly at the sun, or even to look
at reflections of the sun off of water, ice, or snow, as this can directly damage the
retina.
-
Intra-ocular lens implants after cataract surgery often include a
substantial ultraviolet filter. Nevertheless, sunglasses will
protect the parts of the eye not protected by the implants.
It is important for parents to understand
the danger of ultraviolet light, and the importance of protecting
children's eyes now, when it will offer the most benefit.
Polycarbonate lenses offer built-in ultraviolet protection, as well as
being the best shatter-proof safety glasses. Even if a child does
not require a prescription, using zero (plano) powered polycarbonate
lenses offer excellent protection. Frames suitable for children's
faces are widely available.
Skiers and
snowboard riders must wear sunglasses or goggles to protect the eyes from
ultraviolet light. Goggles protect the entire ocular area from
injury, so they are the most highly recommended. They can be
obtained with or without a prescription. Some high-tech products are
available, including one goggle with a tiny battery-powered fan that draws
out moisture to eliminate fogging. Other goggles offer double lenses
to eliminate fogging
"Snow blindness", or
photokeratitis, is similar to flash burn, caused by a welding arc.
This is due to an excessive exposure of ultraviolet light onto the cornea.
Skiers, snowboard riders, and those who live in cold, snowy regions and
spend time outdoors, are at increased risk for photokeratitis.
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Snow reflects more ultraviolet radiation than any other surface.
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High exposure to ultraviolet can cause a corneal burn within one hour,
although symptoms may not appear for six to 12 hours.
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Symptoms include excessive tearing, pain, redness, swollen eyelids,
pain when looking at light, headache, a gritty sensation, and blurred
vision.
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Treatment may include patching the affected eyes with antibiotic
ointment or solution. The cornea will regenerate spontaneously
within 24 to 48 hours.
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Prevention is much easier than treatment in the case of
photokeratitis.
