Sunglasses have become a staple of modern culture; not just during the summer, but throughout the year. Children and adults from all different lifestyles can be seen wearing these darkened spectacles, but what is it that sunglasses actually do? And, how did sunglasses come to be such a popular expression of style?
Did you know: Sunglasses were first used by judges in Chinese courts to conceal their facial expressions while questioning witnesses?! While they serve a significantly different purpose today, sunglasses have become an important part of eye protection. Here's why:
Sunglasses minimize the exposure to sunlight, especially ultraviolet rays that cause both short and long term ocular problems. Experts suggest wearing sunglasses that relflect or filter out 99-100% of UVA and UVB light. This light, having wavelengths of 400 nanometers (a unit of length in the metric system), can be blocked with sunglasses labeled UV400.
Light is broken into three different types: UVA, UVB, and UVC. UVA has longer wavelengths and passes through glass easily. UVB rays are the most dangerous, as they don't go through glass. These types of rays make sunglasses a must. UVC rays don't reach the earth because of atmospheric blockage.
Utilizing polarized and anti-reflective sunglasses greatly reduces severe glare. Light that is reflected from surfaces like a flat road or smooth water is generally horizontally polarized. The horizontally polarized light from these surfaces is blocked by the vertically oriented polarizers in the lenses of these types of sunglasses. Anti-reflecting coatings reduce glare that comes from light reflection off the back surface of the sunglass lenses. Both of these types are of great benefit when doing activities on water, snow, or driving.
History of the Style
Did you know: Sunglasses were first used by judges in Chinese courts to conceal their facial expressions while questioning witnesses?! While they serve a significantly different purpose today, sunglasses have become an important part of eye protection. Here's why:
Sunglasses minimize the exposure to sunlight, especially ultraviolet rays that cause both short and long term ocular problems. Experts suggest wearing sunglasses that relflect or filter out 99-100% of UVA and UVB light. This light, having wavelengths of 400 nanometers (a unit of length in the metric system), can be blocked with sunglasses labeled UV400.Light is broken into three different types: UVA, UVB, and UVC. UVA has longer wavelengths and passes through glass easily. UVB rays are the most dangerous, as they don't go through glass. These types of rays make sunglasses a must. UVC rays don't reach the earth because of atmospheric blockage.
Utilizing polarized and anti-reflective sunglasses greatly reduces severe glare. Light that is reflected from surfaces like a flat road or smooth water is generally horizontally polarized. The horizontally polarized light from these surfaces is blocked by the vertically oriented polarizers in the lenses of these types of sunglasses. Anti-reflecting coatings reduce glare that comes from light reflection off the back surface of the sunglass lenses. Both of these types are of great benefit when doing activities on water, snow, or driving.
History of the Style
The beginning of this article mentions the first known uses of sunglasses by Chinese courts. But what about from there on? Information from Sunglass Internationals notes that the turn of the 20th century caused the widespread use of sunglasses as early silent movie stars began wearing them before filming to shield their eyes from the stage lights.
Cheap sunglasses (not the ZZ Top song!) were first manufactured in 1929 by an American man named Sam Foster, whose primary purchasers were beach goers in New Jersey. This was the defining time of sunglasses as a fashion accessory. Polarized lenses crept into the scene in 1936 from developer Edwin Land, who patented the Polaroid filter.
Cheap sunglasses (not the ZZ Top song!) were first manufactured in 1929 by an American man named Sam Foster, whose primary purchasers were beach goers in New Jersey. This was the defining time of sunglasses as a fashion accessory. Polarized lenses crept into the scene in 1936 from developer Edwin Land, who patented the Polaroid filter.
The biggest promotion for the accessory use of sunglasses is thought to be from WWII, when prominent military figures such as General MacArthur were seen wearing them. The popular wartime image made them a desirable item for youth and young adults.
Ever increasing styles, materials, and varieties of sunglasses are being made everyday. Remember: eye damage is cumulative, meaning it increases from year to year, so the sooner you protect your eyes, the better.
For more information on eye protection, eye damage, and medical conditions or treatments, visit our complete online health library.
Ever increasing styles, materials, and varieties of sunglasses are being made everyday. Remember: eye damage is cumulative, meaning it increases from year to year, so the sooner you protect your eyes, the better.
For more information on eye protection, eye damage, and medical conditions or treatments, visit our complete online health library.
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