What is Polarization
Polarization is when light strikes a surface. All the
photons are vibrating in one direction instead of in random directions. The
light travels from ‘pole to pole’ along that plane. This is what causes the
glare off of shiny objects like Automobiles, chrome, and the shiny reflection
off of water. That’s what causes the mirror like effect on top of water that
prevents you from seeing through the waters surface. This glare distorts the
color of objects and makes them harder
to distinguish.
What does a polarized lens do
Polarized lenses work by filtering the waves of light by
absorbing some of the reflected glare while letting some of the other light waves to pass through them. One way to
think of how a polarized lens would work is to think of the Polarized lens as a
window blind. A window blind will block
light that strikes it from certain angles, while allowing light to pass through
from other angles. A polarizing lens will work when it is positioned at a 90
degree angle to the source of the glare. Polarized sunglasses are designed to
filter out horizontal light and the polarized lenses are mounted verticaly in
the frames and they must be carefully aligned so they will filter out the light
waves.
How are polarized sunglasses made
The first polarized lenses were a piece of polarizing film sandwiched
between two layers of flat glass. Because glass lenses are so heavy, thinner
and lighter plastic and polycarbonate lenses have become so popular.
Early polarized sunglasses had problems with delamination,
which is the separation of the polarizing film from the glass or plastic
lenses. The making of modern lenses have solved this problem, the polarizing
film is suspended inside the mold and the plastic is melted and poured in. The
plastic then hardens around the piece of suspended polarized film, creating a
solid material, rather than a layered one. Polycarbonate lenses are injection
molded, so they are made a little differently. The heat from the injection
molding would destroy the polarizing film, so the polarizing film is applied to
the front of the lens and covered with a scrach resistant coating.
Polycarbonate lenses are the lightest and thinnest polarized lenses available.
Who benefits from polarized sunglasses
Polarized lenses work well for for boaters, fishermen,
skiers, golfers, bikers, and joggers, who require a clearer view and
elimination of glare. These sunglasses when used for driving, can reduce the
glare that comes off the car or the surface of a road. Polarized sunglasses can
also be used indoors by light sensitive people. While ordinary tinted lenses
reduce brightness, only polarized lenses eliminate glare. While the first
polarized sunglasses were used mainly by sportsmen, the general public has
realized it’s many benefits, and now they have become so popular.
Posted by Kenny D. VanWormer on November 14, 2010 at 6:10 PM under
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