Sunprotection with a diopter
You can fit tinted or photochrome lenses with any diopter into an appropriate frame to protect your eyes from the blinding sun. If you want to go to the beach, feel the smell of the sea, have a rest, escape from problems or find a new image, no doubt, you need sunprotective glasses with your diopter.
Hard shortwave radiation is stopped by the atmosphere and mostly doesn’t reach the Earth’s surface. Most work materials of the lenses filtrate hard ultraviolet perfectly. But this function is important only high in the mountains or in the Anterctic. Radiation can be undoubtedly dangerous in the processes of metal welding and direct observation of the Sun. In such cases you need special filters, not sunprotective glasses.
This spectrum provides you with suntan and destroys bacteria. Lenses must protect your eyes from this very spectrum.
Even white and coated lenses weaken the impact of ultraviolet A considerably. Nontransparent work materials, such as wood or metal, provide 100% protection. “100%” label on the lens in reality means weakening of UV radiation according to the EU requirements. But how can you check it on?Current optical devices and testers for checking lenses’ protection level use available LED transmitters with the wavelength of 375-420 hm, i.e. measurements are taken on the line between visible and ultraviolet spectra. As a result, 90% protection means both EU and all-Union State Standard multiple overmatch. No manufacturer wants to hazard reputation. So, even affordable mass brands provide eye protection. During our years of work experience we have come across low protection level lenses only several times. They were always mineral lenses (glass), fake popular brands. Color rendering, working lifespan, level of darkening, optical quality and functionality are really more important. Negative effect of ultraviolet accumulates. That is why, the longer you wear glasses the better.