subject: Some tips about polarized sunglasses in the market [print this page] Polarized sunglasses, like lots of great inventions, are used by lots of of us without a second thought. But did you ever cease to think about where polarized sun shades come from? Somebody had to come up with them.
Actually, they owe the creation of polarized sunglasses to two men. In the 1750s, James Ayscough experimented with using tinted glass to correct vision issues.
Lots of scientists of the time were studying the properties of light & color. In 1808, Etienne-Louis Malus, a French physicist & mathematician, they discovered that light waves from the sun, which usually vibrate in all directions, can be aligned in to one direction when it is reflected off something, like water. According to Malus' law, the intensity of light transmitted through a polarizing filter depends on the angle of the filter in relation to the light.
While Malus' law is important in the study of optics, it remained for Scottish physicist, astronomer & inventor Sir David Brewster to discover the angle at which light with a specific polarization can be transmitted through a surface with no reflection. This they did in the year 1815. The angle, called Brewster's angle or the polarization angle), is critical in the invention of polarized sun shades.
Throughout the 19th & early 20th centuries, experiments continued. People began using yellow- or brown-tinted sun shades to counteract light sensitivity. People realized that color had something to do with polarization. The optical company Bausch & Lomb began producing a dark green glass to protect U.S. Army Air Corps pilots from glare at high altitudes.
Some tips about polarized sunglasses in the market
