Sunglasses are not only stylish fashion accessory and essential tool to protect the eyes from ultraviolet radiation. Many people mistakenly think that the UV-rays are stronger during the summer. This is not true.Determining how long you spend in the sun, whether summer or winter.Therefore, the glasses always so important to quality.
The windows of the sunglasses is advisable to have glass. Latest plastics of course are not so bad, but on them quickly appeared scratches. The glass can be easily distinguished from the plastic by weight: it is much more difficult. Apart from that glass must have 100% UV protection. Glass from polymers such as CR- 39 and C-13 used most professional athletes who spend a long time in the sun. Mirror lenses are spectacular, but still do not provide 100% protection.The degree of protection, which is usually indicated on the handle, label or the passport of the glasses does not depend on the color of the glass. Look for sign UV 400! It means that in the chemical composition of the glasses includes additives that provide as 100% protection.
The retro sunglasses with plastic frame are more fragile as opposed to those whose frames are made of metal. Until recently nontraditional materials such as rubber and titanfleks easily recover shape after bending or distortion, while plastic does not possess such properties. That is why in the first place is, of course, the metal – the most expensive and most reliable material for frames. To not have itching in the nose, choose glasses with protivoalergenno coverage (for it is issued a special certificate).
It has been shown that yellow, pink and orange glasses are harmful. Yellow instance stimulates the retina, causing optical stress. Green sunscreen filters have a healing effect because lower eye pressure. For the retina of the human eye is most suitable neutral greyscale. Such filters do not change the natural color…