A, see packaging.
If there is a manufacturer and address on the package and label.
Second, look at the lens.
If there is a scratch on the lens, magazines, bubbles, stripes.
Three, see color.
Black, dark brown, gray filter effect is better.
Wear dark brown lenses can improve visual contrast and clarity, wear suitable for the fog.
Fourth, sunscreen has nothing to do with the colour.
When buying, should choose to have UV resistant lenses.
Five, and the choice of using polarizing lens sunglasses.
Using polarizing lenses can effectively filter out reflected light and the ultraviolet ray, and has broken wear prevention, and other functions.
Glasses sunglasses factory warm prompt: the sunglasses on the market quality good and bad are intermingled, the inferior sunglasses don't keep out the light not only, even after wear has a great effect on the eye.