| SUNGLASSES WITH POLARIZED LENSES ARE NOT JUST GOOD FOR YOUR VISION, THEY MIGHT EVEN SAVE A LIFE |
| THIS PHOTO TAKEN WITH SUNGLASSES THAT DO NOT HAVE POLAR FILTERING |
| THIS PHOTO TAKEN WITH SUNGLASSES THAT HAVE POLAR FILTERING |
POLARIZED TECHNOLOGY
Here is the major distinction that differentiates
polarized lenses from conventional sunlenses:
Polarized lenses have an uncanny ability to block
reflected light. They are able to selectively block
sunlight reflected from horizontal surfaces
(commonly defined as glare).
If there is no glare, polarized lenses function like
conventional sunlenses. But when sunlight is
reflected from horizontal surfaces, the polarizing
filter steps into action and functions like a
Venetian blind, blocking the light rays.
It was Edwin Land (inventor of Polaroid Instant
Cameras) who in 1935 discovered a way to create
a man-made polarizing filter. The filter consists of
a thin plastic sheet made up of uniformly aligned
needle-shaped crystals. The parallel rows of
crystals permit light rays oriented in only one
direction to pass through while blocking light in
the opposite meridian--like a Venetian blind.
For sunglasses, the film is oriented in the lens so
that horizontal light rays (reflecting from horizontal
surfaces) are blocked. During manufacturing, the
thin polarizing film is suspended in the mold just
behind the front surface. When the lens is cast, the
film becomes an integral part of it. This "in mold"
process replaces lamination and eliminates the
tendencies of polarized lenses to separate or
delaminate
Here is the major distinction that differentiates
polarized lenses from conventional sunlenses:
Polarized lenses have an uncanny ability to block
reflected light. They are able to selectively block
sunlight reflected from horizontal surfaces
(commonly defined as glare).
If there is no glare, polarized lenses function like
conventional sunlenses. But when sunlight is
reflected from horizontal surfaces, the polarizing
filter steps into action and functions like a
Venetian blind, blocking the light rays.
It was Edwin Land (inventor of Polaroid Instant
Cameras) who in 1935 discovered a way to create
a man-made polarizing filter. The filter consists of
a thin plastic sheet made up of uniformly aligned
needle-shaped crystals. The parallel rows of
crystals permit light rays oriented in only one
direction to pass through while blocking light in
the opposite meridian--like a Venetian blind.
For sunglasses, the film is oriented in the lens so
that horizontal light rays (reflecting from horizontal
surfaces) are blocked. During manufacturing, the
thin polarizing film is suspended in the mold just
behind the front surface. When the lens is cast, the
film becomes an integral part of it. This "in mold"
process replaces lamination and eliminates the
tendencies of polarized lenses to separate or
delaminate
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