The sun glasses to choose techniques

The sun glasses to choose very learned, improper choice to cause damage to the eyes, so I pay special attention to when choosing sunglasses. Should choose to normal store had normal manufacturer production sunglasses with uv protection functions. Small street vendor, vendor selling glasses, often cannot achieve the standard of uv protection, good not to choose and buy. Pay attention to the lens surface to be smooth when the choice, no ripples, no defects, no bubble, no grinding crack. Lenses to flat, from horizontal direction observation lens without warp. Uneven or signs of unfavorable choose and buy, bubble lenses. Lens color options, should be put on after the distortion of the color of the surrounding environment, the edge of the object is clear, can effectively identify the different color lights for the principle. Lens color shades of choice, should depending on the activity place, generally at a moderate depth of well, such as light gray, light brown, light green, the color of the sunglasses for infrared, ultraviolet absorption is good. If required, of course, shading effect is very strong, you should select the darker lens. But cycling lenses or drivers can't choose the color is too deep, otherwise cannot effectively identify different colors of traffic lights. In addition, when the choose and buy sunglasses have to consider and size, face, eyebrows, eyes, nose, the matching relationship between. Usually, people want to choose a big picture frame sunglasses with big eyes, small eyes some choice some sunglasses frames; Round face fat people wear bulky frame sunglasses, slender face for circular frame sunglasses, oblate, appropriate chooses and narrow face people square frame sunglasses. Of course, if the face computer every day, you can also choose to with the function of radiation protection glasses sunglasses!