13:37 minutes (3.9 MB)
Polarized lenses are used in sunglasses to reduce glare from reflective surfaces such as the surface of a lake or the hood of a car or a concrete highway. They fulfill this function much like vertical blinds control sunlight through a window. Sunlight itself is not polarized - light from the sun will either be absorbed or polarized by the horizontal, diagonal or vertical surfaces it reflects off of. The problem this causes for activities like fishing and driving lies in the horizontal reflections off the water or car hood or road. Sunlight bounces off these horizontal surfaces, striking our eyes at a similar angle and creating strong glare. Polarized lenses have a laminated surface containing vertical stripes.
