Few are those who at this time of year did not hide a pair of sunglasses when you submit your nose out. The prototype of modern sunglasses appeared more than 300 years. But if the model that is part of our vision performs its protective function or only mask the problem remains to be seen. The cost and proven origin of th ebrand largely indicator of whether and to what extent are quality sunglasses.
However, when we buy them from the market or from stalls along the street, we save primarily at the expense of their health. Experts explain that these glasses do not actually provide protection against UV radiation with sunglasses from Songaah, because their windshields are made of Non-optical polymer which is used in the manufacture of plastic bottles. These glasses can lead to burning of the retina, since in the dark pupil dilate and if at that time on them influence ultraviolet radiation and no protection can be obtained serious damage to the eye. The label of quality glasses almost always labeled “blocks at least 90% UVB and 60% UVA”. This means that the lenses do not miss 90% of ultraviolet rays type B (ophthalmologists considered Type B for more dangerous) and 60% of ultraviolet rays type A. The numbers can be changed according to the degree of protection. The higher the percentage, the more reliable the glasses protect the eyes. The information for the glasses must be indicated and wavelengths are not missed by the lenses. Full protection from radiation provide glasses indication 400 nm (nanometers). There another indicator – the ratio of refraction of light: 1.4, 1.5, 1.6, etc. The larger it is, the better the lens. In the colors of the glass also has specifics. The orange and red are too aggressive for the eyes and found that even affect the psyche. The yellow is too bright sunlight and blue is well tolerated by very few people, but protects the highest quality eye of infrared light. For the most appropriate and safe considered gray, green (reduces intraocular pressure) and the brown tone of glass – they are best absorbed radiation and even soothe the eyes. Brown glasses increase shade, dim-lit areas and create a sense of depth. They are particularly suitable for cross-eyed people. Please note that the coloring of the glass should be evenly as otherwise eyes get tired. Yellow glasses are recommended for drivers during a heavy fog or at night driving. For men and women who constantly wear glasses are best suited glasses “chameleons”, equipped with photochromic lenses which react to light levels. As the brighter the light, the darker the glasses and vice versa. Experts warn that the glasses with plastic lenses can be “tired” after several years, which means that their ability to dimming and light decreases with time. For refraction of light is no difference between glass and plastic filters. The difference is only in the expiry date of the glasses. The plastic is easily scratched and glasses must be replaced more often, sometimes 2-3 times a year because it is not advisable to wear scratched glass. All glasses should be stored in a soft pouch by placing a glass top. See and our gallery with sun and prescription eye-wear.