Different types of sunglasses
Article Tags: Sunglasses
Types of ultraviolet rays
There are three types of UV rays, namely UVA, UVB and UVC, all of which are located just behind the violet portion of the visible spectrum. UVC rays are blocked by the earth’s atmosphere but UVB rays are quite dangerous. UVA ray is the most widely recognized and known by ordinary people. Even if these three forms have different popularity, they can all cause damage to the eyes. As a result, it is advisable to choose sunwear capable of blocking all these rays. Spending much time on outdoor games or sports, children with sensitive eyes especially need adequate UV protection from sunglasses.
What makes sunglasses particularly necessary?
During 10 am and 2 pm when sun rays are the most intensive, sunglasses are necessary to get UV protection. Whether it is overcast or sunny, UV light can go through the clouds, so that it is necessary to wear sunglasses even in an overcast day. Some factors impose a higher risk of UV light on human eyes, including sunlamps, tanning beds and parlors, living at high altitudes or near the equator. People involving any of these conditions need extra protection from sunglasses. In addition, people with cataracts, macular degeneration or retinal dystrophies should pay extra attention to UV rays.
Sunglasses that block blue light
Sunglasses are available in various colors and styles. Blue-blocking sunglasses can keep the wearer away from blue light, which is thought to increase the risk of developing disease-caused eye damage. The capability of blocking blue light is always incorporated together with UV protection. These blue-blockers are preferred by skiers, hunters, boaters and pilots. Bothersome glare can be cut by either polarized lenses or lenses with anti-reflective coatings.
Sunglasses with a mirror coating
Mirror-coated lenses can prevent a significant amount of unwanted light from entering the eyes. Applied to the front surface of lenses, these highly reflective coatings are particularly beneficial during activities in bright conditions. Such a reflective coating will help avoid direct sunshine on the eyes. The color of mirror coating can also be cosmetic, without any influence on color perception.
Sunglasses using gradient lenses
Darkest at the top, gradient lenses can protect the eyes against overhead sunlight and allow more light through the bottom half. This feature makes gradient lenses the best choice for driving. Double gradient lenses have two darkest parts at the bottom and the top, while the middle part is lighter.
Photochromic lenses change their colors in accordance to external UV ray amounts. Being in an outdoor environment with UV light, these lenses will darken and function as sunglass lenses. Magically, they will then become clear when UV rays are removed and serve as regular prescription glasses.
For eye safety, impact-resistant lenses are necessary either on the job or during sports. In general, sports eyewear made of special materials is safer than ordinary eyeglasses. Performance sunglasses can even improve the vision, so that they are widely enjoyed by athletes and sports fans.