Lenses Should Block Ultraviolet Rays
The sun’s rays emit ultraviolet (UV) radiation, which human eyes can not detect or can not feel. The sungiasses, which allow us to protect our eyes from the sun, must have UV protection and must be suitable for our eyes. The sunglasses absolutely must be certified regarding cutting off UV or ultraviolet rays. Normally every lenses can block UV at different rates, however special coatings must be reguired for effective UV blocking system.
The power of the sunglasses to block the light is indicated by inscriptions such as UV200, UV400 and UV600. Especially at the seaside and when we are skiing, sunglasses with minimum UV400 protection are reguired.
CE (European Conformity) Certificate
Ouality sunglasses must have a reliable registration certificate, Since 1995, CE (European Conformity) is marked on quaiity sunglasses according to European Union standards. The CE cenificate states that the product meets the minimum safety requirements, When buying sunglasses, make sure that the lenses are stained and mica, and check if there are scratches, blisters and curvatures on the lens.
Lenses Shouid Focus 0n A Vertical Line
Another way to understand quality is to focus on a vertical line after wearing the sunglass. In this case,when you move the sunglass, which is without prescription, the image does not move, as well. When you move sunglass slightly up and down or right to left, if there are refractions in line, then the sunglass isn’t suitable.
Light Absorption Rate Shouid Be Appropriate
The ‘light absorption rate’ in the operating instructions indicates how much of lenses absorb, how much reflect and how much light comes from outside, 40-50 percent in urban environment, 50-70 percent in mountain ous regjons where sun rays come steeper, 80-85 percent absorption by sea and skİİng are sujtable,
Every Expensive Sunnies Doesn’t Refer Good Ouality
İt is not enough for the sunglasses to prevent excess light from passing. On the contrary it harms, Because when the colored lens is attached, the pupil does not shrink, Thus, harmful UV rays enter the eye in abundance, A sunglass needs to be certified for quality and UV blocking.
Sunnies Lens Type Doesn’t Provide Extra Protection!
Since mirrored lenses reflect some of the light coming into the eye, they can be preferred especially at the seaside where there is intense light . However, mirrored coatings reduce the amount of light to the eye, but do not affect the UV blocking rate, Although polarized lens feature is not normally associated with UV blocking, both poiarized and effective UV lenses provide safer and better viewing comfort.