Polarized sunglasses, like many great inventions, are used by many of us without a second thought. But have you ever stopped to think about where polarized sunglasses come from? Someone had to come with them.
Actually, the creation of polarized sunglasses we owe to four men. In the 1750s, James Ayscough experimented with using tinted glasses to correct vision problems.
Many scientists at the time were studying the properties of light and color. In 1808, Etienne-Louis Malus, a French physicist and mathematician, discovered that light waves from the sun, which normally vibrate in all directions, can be aligned in one direction when reflected off something, such as water. According to Malus’ law, the intensity of light transmitted through a polarizing filter depends on the angle of the filter relative to the light.
While Malus’s law is important in the study of optics, it was left to Scottish physicist, astronomer, and inventor Sir David Brewster to discover the angle at which light of a particular polarization can be transmitted through a surface without reflection. This he did in the year 1815. The angle, called the Brewster angle or polarization angle, is instrumental in the invention of polarized sunglasses.
Throughout the 19th and early 20th centuries, experiments continued. People started wearing yellow or brown 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 US Army Air Corps pilots from glare at high altitude.
However, it wasn’t until 1936 that Edwin H. Land, an American inventor, created a polarizing light filter that was light enough and inexpensive enough to use in sunglasses. He later created the Polaroid Corporation and developed many inventions, including the Land Camera, which allowed amateur photographers to watch their images 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 looked down at his instrument panel. Army pilots were given these glasses for free, and as their popularity grew, Ray Ban soon began selling them to the public. Polarized sunglasses helped pilots see and complete their missions safely. Their ultra-modern and effective glasses added to the mystique of the pilots and soon everyone wanted them to imitate their heroes.
Polarized sunglasses are a fashion trend that continues to serve a useful purpose.