The following is a short writing on the protection that sunglasses offer,
It has been hypothesized that ultraviolet light induces cataracts in human
lenses. Cataracts are cloudy formations in the lens that, if severe, will
require surgery to remove and restore clear vision. Experiments on guinea
pigs done with UV absorbing contact lenses in one eye protected against
cataract formation where the other unprotected eye developed cataracts.
Light with wavelengths of 300nm and above can pass through the cornea and
lens. It is believed that light of 300-320nm can possibly be damaging to
the lens. (The lens acts as a filter protecting the retina from
light-induced damage; people who have their lenses removed (aphakic) are
more susceptible to retinal damage; that's why plastic lens implants have
UV absorbers added).
Another effect of the sun on your eyes is pterigium - abnormal growth of
the surface of the eye which can invade the cornea causing loss of vision
necessitating removal of the growth - caused by longtime sun exposure.
So how do we protect our eyes? Certain researchers are skeptical of the
protection offered by common sunglasses. Consider this: common (nearly
sunglases may actually cause more harm than good. Why? The sum-shading
causes the pupil to widen, allowing maximum light in so you can see and
bump into walls with your sunglasses on. Unfortunately, light can shine
in through the unprotected sides of your face and reflect directly into
your wide open pupil. This is similar to (but not as severe as) looking
directly at a solar eclipse (the lack of a bright sky allows your pupils
to open wide giving the lens and retina a full blast of radiation).
Being on land on a bright sunny day is hard enough on your eyes, but being
the water is doubly dangerous (light reflects from the surface of the
The wise sailor would be good to purchase the wrap-around type of
that filter ultraviolet light coming from all directions. Keep them in a
good case in your car for driving to the beach, and then use a tight or
floatable croakie-thing so you don't donate them to the fish while
Take care of your eyes, God only gave you two and they are fuzzy enough
fellow windsurfer in the Chesapeake Bay area.