Polarized Sunglasses
Glare free polarized sunglasses will cut out the glare from the sun reflecting off
the road and the car's hood. Too much of this type of glare can easily
fatigue the eyes and make you sleepy while driving during the day. Since
they can make you a safer driver, they are very good for truckers, taxi
drivers or anyone that does a lot of day time driving.
Most fishermen wish they could see the fish in the water,
but can't because of the glare of the sun reflecting off the surface
of the water. Wearing regular sunglasses help a little, but still can't
overcome the glare enough to be able to see the fish. We now have special
nonglare polarized sunglass which cuts out almost all of the reflected
surface glare allowing the fisherman to see exactly where the fish are.
Regular boaters love these glasses as well because removing the surface
glare just makes boating that much more fun.
What makes polarized sunglasses different than regular sunglasses? Regular
sunglasses absorb a certain percentage of the various wave lengths of
light. If the sunglass is grey, that means it absorbs all the wave lengths
equally. This is generally the most popular color because the color values
have not been altered. The second most recommended color would be green,
which means it absorbs green the least and the other wave lengths more.
Green is in the middle of the visual spectrum which is the safest most
comfortable color for the eyes. It is more effective at blocking out
the infrared and ultraviolet rays which are at the ends of the visual
spectrum and are the most harmful.
When sunlight strikes a surface like smooth water, the more vertical
rays enter the water and are transmitted to objects like fish that are
beneath the surface that absorb these rays. The more horizontal rays
that are reflected off the surface become reflected glare. These rays
are called polarized because they do not contain the vertical component.
Sunglasses that are made to transmit the vertical component only and
absorb the horizontal rays are polarizing sunglasses.
To better visualize this, imagine sunlight coming thru an unobstructed
window. Then imagine behind that window a horizontal venetian blind where
the slats were partially opened and horizontal slits of sunlight are
shining thru. These horizontal slits of light you can think of as polarized,
because there is no vertical component just like the light that reflected
off the water. Now imagine that behind the horizontal blind there is
a partially opened vertical venetian blind that cuts down on the horizontal
slits much like the polarizing sunglasses that transmits the vertical
component and cuts down the horizontal portion. In other words the horizontal
blinds cut down the vertical component and the vertical blinds cut down
the horizontal component to where virtually no light would enter the
room. The polarized sunglasses work like the vertical venetian blind.
They allow the vertical component that has entered the water to enter
the eye, but they cut out the horizontal component that has reflected
off the waters surface that became the glare.
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