Yes. The sun has damaging UV rays that can cause:
-
Photokeratitis, basically "Sunburn of the cornea", which can
cause temporary vision loss that can result is referred to as "snow blindness."
-
Pingueculae
-
permanent
retinal
damage.
What exactly are UV rays?
Ultraviolet (UV) rays are located just past the violet portion of
the visible light spectrum; sunlight is the main source.
UV light is broken into three different types: UVA, UVB and UVC. UVA
has longer wavelengths and passes through glass easily; experts disagree about whether
or not UVA damages the eyes. UVB rays are the most dangerous, making sunglasses and
sunscreen a must; they don't go through glass. UVC rays do not reach the Earth because
its atmosphere blocks them.
When do UV rays affect my eyes?
Most people think that they're only at risk when they're outside on a
sunny day, but UV light can go right through clouds, so it doesn't matter if the sky is
overcast. The sun's rays are strongest between 10 am and 2 pm.
Glare and reflections can give you trouble, so have your sunglasses
ready if you'll be around snow, water or sand, or if you'll be driving (windshields are
a big glare source).
The following put you at additional risk: sunlamps, tanning beds and
parlors, photosensitizing drugs, and living at high altitudes or near the equator.
What are my options to prevent damage to my eyes?
You must wear sunglasses to prevent damage to your eyes. While some
contact lenses provide UV protection, they don't cover your whole eye, so you still need
sunglasses.
Look for sunglasses that protect you from 99 percent to 100 percent of
both UVA and UVB light. This includes those labeled as "UV 400," which blocks all light
rays with wavelengths up to 400 nanometers. (This covers all of UVA and UVB rays.)
Also, you may want to consider
wraparound sunglasses to prevent harmful UV rays from entering around the frame.
What are the different kinds of lenses that are available?
With so many lenses available, it is difficult to find ones that will
protect your eyes if you don't know what each one will do.
Both polarized lenses and anti-reflective coating cut reflected glare.
Polarized lenses in particular are popular with those who play water and snow sports.
Read more about
polarized lenses and
anti-reflective coating
Mirror-coated lenses limit the amount of light entering your eyes, so
you're more comfortable.
Gradient lenses are tinted from the top down, so that the top of the
lens is darkest; they're good for driving. Double gradient refers to lenses that are
also tinted from the bottom up: the top and bottom are darkest and the middle is clear
(or close to it); double gradients are not very useful for driving, because they make it
difficult to see the dashboard.
Photochromic lenses adjust their level of darkness based on the amount
of UV light they're exposed to.
Read more about Photochromic Lenses...
Which lens color is the best?
Color is a personal choice and doesn't affect how well the lenses
protect your eyes from UV light. Gray and brown are popular because they
distort colors the least. Athletes may choose other tints for their
color-enhancing properties; for example, yellow lenses are popular with
skiers and target shooters because they work well in low light, reduce
haze, and increase contrast for a sharper image.
Read more about lens color..
Do I still need those "UV Protective" sunglasses if my lenses are
real dark?
Yes! Most people believe that the darkness of the lens is what
protects
their eyes. The degree of darkness has no effect on UV rays. For
adequate protection, you need to buy sunglasses that indicate they block
100 percent of the sun's UV rays.
Children don't need sunglasses, do they?
Children are at particular risk because they're in the sun much more
than adults, and their eyes are more sensitive as well. UV damage is cumulative over a
person's lifetime, which means you should begin protecting your child's eyes as soon as
possible.
Most parents would not allow their children to go outside without
shoes, yet many seem unaware of the need to protect their children's eyes.
Read more about children's sunglasses..
I wear glasses. What options are available to me?
You can buy prescription sunglasses or glasses with photo-chromic
lenses
(which change from clear to dark) from your eye care practitioner.
Clip-ons are a less expensive option, and can be bought at the same time as your
regular eyeglasses to perfectly match the frames. Magnetic attachments may also be
available. Read more about
prescription sunglasses and
photochromic
lenses.
