By: Evan Wise
Most people want polarized sunglasses but don’t know why or what they really do. Here is a brief explanation:
Light is both a particle (photon) and a wave (photons travel in a wave pattern). The waves vibrate in random directions in sunlight and vibrate in all directions. When light reflects off of a surface like a car in front of you or a window or mirror, for example, the waves line up and vibrate more in one direction. Your eyes can’t tell the difference between glare from reflected light that is lined up and ambient or normal light that is not lined up in one direction.
Polarized sunglasses act like a filter. They only let light through that is lined up in one direction. Your sunglasses filter out light that is lined up in the direction of reflected light or glare. That means that when you are driving, your sunglasses remove most of the reflected light but let through the random light so you can see clearly without being blinded by the glare…
If you are interested you can try a simple experiment. Take two different polarized lenses and hold them up to the light. Now rotate one lens as you look through both lenses. If they are polarized, you should see darker and lighter as you rotate the lens. This is because the first lens is removing light that is not lined up they way the polarized lens is. When the second lens is lined up with the first lens, all the light is transmitted through both lenses and you see light. When the two lenses are at 90 degrees to each other, the first lens takes out all the light except the light in one direction. The second lens then removes the light that was transmitted by the first lens and the lenses look dark.