We need light to see. That much we all know. The thing is, not all light is the same to the human eye. There’s light the eye can use, and there’s light that makes it hard for the eye to do its job. When sunlight reflects off horizontal surfaces like tarmac, water, pavement or even grass, much of it is concentrated in horizontal waves. This horizontally polarized light is seen as annoying glare. This glare masks useful light which is travelling in the vertical direction. The result is, you can’t see properly, and you tend to squint or just close your eyes. And you don’t even need a sunny day. You can get glare on overcast days because light still reflects off horizontal surfaces and becomes concentrated in the horizontal direction. Polarized sunglasses have a special polarizing filter in the lens that blocks horizontally reflected glare and lets in vertically travelling light that the eye can use. A lot of science goes into polarized sunglasses, but what you notice is that compared to ordinary sunglasses things just look clearer. And, your eyes will be more comfortable.
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Rainbows and Polaroid sunglasses – a trick of the light? » Polaroid Sunglasses says:
February 9, 2010 at 12:54 pm
Comments[...] the core of every pair of Polaroid sunglasses is a unique polarizing filter that blocks glare - reflected light that’s traveling in the hoizontal plane. It’s this polarizing core that stops you from squinting in bright light. It was Edwin Land, [...]