Polarized sunglasses, like many great inventions, are used by many of us without a second thought. But did you ever stop to think about where polarized sunglasses come from? Somebody had to come up with them.
Actually, we owe the creation of polarized sunglasses to four men. In the 1750s, James Ayscough experimented with using tinted glass to correct vision problems.
Many scientists of the time were studying the properties of light and color. In 1808, Etienne-Louis Malus, a French physicist and mathematician, he discovered that light waves from the sun, which usually vibrate in all directions, can be aligned into 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 and inventor Sir David Brewster to discover the angle at which light with a particular polarization can be transmitted through a surface with no reflection. This he did in the year 1815. The angle, called Brewster’s angle or the polarization angle), is critical in the invention of polarized sunglasses.
Throughout the 19th and early 20th centuries, experiments continued. People began using yellow- or brown-tinted sunglasses 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.
However, it wasn’t until 1936 that Edwin H. Land, an American inventor, created polarizing light filter that was light and inexpensive enough to use on sunglasses. He later created the Polaroid Corporation and developed many inventions, including the Land camera, which allowed amateur photographers to watch their pictures develop instantly.
Land’s invention was quickly put to use in sunglasses produced by Ray-Ban, a unit of Bausch & Lomb. Ray-Ban also created the distinctive “aviator” frame that protected a pilot’s eyes as he repeatedly glanced down at his instrument panel. Army pilots received these glasses for free and as their popularity grew, Ray Ban soon began to sell them to the public. The polarized sunglasses helped pilots to see and complete their missions safely. Their ultra-cool and effective sunglasses added to the pilots’ mystique and soon everyone wanted them in order to imitate their heroes.
Polarized sunglasses are one fashion trend that continues to serve a useful purpose.