a reduction in stratospheric ozone

Sunglasses are now considered necessary, in order to protect the eyes from harmful UV rays. Although the main purpose of sunglasses to protect the eyes, it needs to match the different clothing or fashion. Shopping sunglasses do not have to be expensive, as can be seen, in the high street shopping and the like. In order to get cheaper alternatives, but still a chic and stylish, online shopping is the key. Online stores can provide cheaper prices than designer glasses, really shop at shopping malls or boutique shopping. Considering the cheap, but fashion glasses, but it still needs of different elements, especially from harmful UV rays, to provide the best protection of eyes. In this regard, should consult with an optometrist or optometrist website, in order to obtain the best advice what kind of glasses.
Typically, an optometrist instructions should be acquired to provide protection, prevention of UV sunglasses. In addition, good optometrist will show their sunglasses, and explains its anti-ultraviolet value. UV400 is considered as a basic protection, protection from the sun's harmful ultraviolet rays. However, not all Sunglasses provide such protection, some are below UV400. However, this does not mean, this kind of glasses is not qualified.
The sun is the main source of ultraviolet or uv. From 320 to 400 nm wavelength range such as UVA, UVB range from 280 to 320 nm and UVC, ranging from 320-400 nm. Basically, UV ray is divided into three categories of wavelength it belongs to. Slightly affected by the concentration of ozone and ultraviolet radiation to tan, skin aging, eye damage and immune suppression. As mentioned above, UV400 can protect your eyes from the damage. Such glasses, to prevent or completely block the light.
UVB, on the other hand, is the effect of ozone is what kind of light level. When there is a reduction in stratospheric ozone, UVB ray can easily reach the earth's surface.