Sun glasses or sunglasses are a type of protective eyewear made primarily to block bright sunlight and/or high-energy visible light from discomforting or damaging the eyes of wearers. They can sometimes function as a vital visual aid as well, because variously termed glasses or spectacles exist, having lenses which are polarized, darkened or colored. In the early 1900s these were known as the sun cheaters, while was cheaters an American slang word for glasses. Many people find that direct sunlight is too bright during their outdoor activities. Healthcare specialists recommend eye protection in the sun to protect yours eyes from ultraviolet radiation rays and blue light, which causes numerous serious eye problems. Sun glasses have been associated with film actors and primarily from their desire to mask themselves in public. Since the 1940s, colored sunglassed have been a popular fashion accessory, more so at the beach.
Protection – How Your Sunglasses Work
Sunglasses utilize a variety of techniques for eliminating problems with light. The following discusses all the different technologies now in use:
- Photochromic lenses
- Scratch-resistant coating
- UV coating
An appropriate pair of sunglasses must do the following:
• Sunglasses provide complete protection from UV rays in the sun. The UV radiation is emitted by the sun and could damage the cornea and retina of your eye. An appropriate pair of sunglasses blocks out all UV rays completely. Beware of the cheap sunglasses because these could do more harm than good. These sunglasses block out some light, allowing the iris to expand however, do not block the UV rays and subsequently increase the exposure to the UV rays.
• Sunglasses provide protection to intense light. When your eye receives far too much light, it reflectively closes its iris. Once the iris has closed as far as possible, the next possible step is squinting. However, if there is again too much intense light, as there could be when sunlight gets reflecting off snow squinting cannot help and this results in damage to you retina. Good sunglasses block light that enters the eyes by as high as 97 percent to prevent damage.
• Sunglasses provide protection to glare. Certain surfaces, like water, reflect a great amount of light, and bright spots form, distracting or even hiding objects from our field of sight. Good sunglasses can eliminate this type of glare completely with polarization.
• Sunglasses eliminate certain light frequencies. Certain light frequencies can blur our vision, which others enhance the contrast. Choosing the appropriate color for the sunglasses lets them perform better in certain situations. Blocking specific light frequencies, these sunglasses help in activities like fishing, skiing and hiking. In conclusion, sunglasses allow some rays to be transmitted while some are reflected away. That occurs at various levels - as the rays hit the exterior of the lens, its interior, and its back side. Sunglasses are classified according to tint, UV absorption and light transmittance.