|
Polarized lenses, reduce glare caused by light reflected from polarizing surfaces such as water as well as by polarized diffuse sky radiation (skylight). This can be especially useful when fishing, as the ability to see beneath the surface of the water is crucial. Polarized sunglasses use the principle of Brewster's angle to reduce glare from the sun reflecting off of horizontal surfaces such as water or road. In a large range of angles around Brewster's angle the reflection of p-polarized light is lower than s-polarized light. Thus, if the sun is low in the sky reflected light is mostly s-polarized. Polarizing sunglasses use a polarizing material such as polaroid film to block horizontally-polarized light, preferentially blocking reflections from horizontal surfaces. The effect is strongest with smooth surfaces such as water, but reflections from road and the ground are also reduced.
 Photographs taken of mudflats with a camera polarizer filter rotated to two different angles. In the first picture, the polarizer is rotated to maximize reflections, and in the second, it is rotated 90° to minimize reflections - almost all reflected sunlight is eliminated. |
