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| Polaroid
Sunglasses |
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One principal use of Polaroid's is to avoid glare of light.
The
light reflected from a bright non-metallic surface (e.g. wet
roads, smooth surface of water, polished tables etc) is partially
plane poliarised with vibration in the horizontal plane. |
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example, if you look at the morning sun reflected from a lake
see the fig, the light waves that vibrate parallel to lake's
surface have larger amplitude than the reflected wave that vibrate
up and down. To reduce the glare of this light, we can wear
Polaroid sunglasses whose transmission axes are oriented vertically.
The glasses then absorb the more intense horizontally polarised
light and thus reduce the glare. This is well-known by fishermen
who wear Polaroid glasses to eliminate reflected glare from
the surface of a lake or stream and thus, see beneath the water
more clearly. Photographers sometimes use Polaroid sheets in
front of lens to reduce the glare of light reflected from a
surface. |
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