1, Anti-ultraviolet function of the sun mirror. Good sunglasses lenses, can block more than 99% of ultraviolet rays, and the logo has UV400 lenses are 100% (99.99%) to block ultraviolet rays. Wear UV-resistant sunglasses, the eyes as if in a darkroom, at this time the pupil will become larger, the residual ultraviolet rays will be injected into the eye, so that the eyes are injured. You'd better go to a store or buy it in a high-profile shop or a flagship store.
Small stall on the must not buy, although those sunglasses can also block ultraviolet rays, but the lens work is not in place, that is unqualified, must not because of cheap to buy it, inferior eyes will cause different degrees of damage to the eye.
2, the transmission than the unqualified sunglasses. After wearing this kind of sunglasses, will produce the traffic signal identification obstacle, extremely easily causes the traffic accident. All sunglasses, including professional driving goggles, motion goggles, fishing goggles ...
(except for myopia and reading glasses) Simple method of identification, can be placed in front of the sun, through the lens to observe distant targets, such as window frames or door frames, and then move the glasses up and down, the lens vision within the target should not swing and wave-shaped deformation.
3. Sunglasses with no category mark. Sunglasses are generally divided into 3 categories, that is, shading mirror for shading, light mirrors for decoration and special mirrors for snow blindness or waterproof plane radiation. If there is no product category identification, consumers can not correctly identify the use of sunglasses when purchasing, affect the use of the effect.
4, to combat the performance of the requirements of the sun-glasses. The lenses are easily broken when subjected to external shocks, which can cause fatal damage to the human eye. Frame material is also very important, generally have plate, aluminum-magnesium alloy, pure titanium. Different needs of the sun requirements are not the same, there are specifically used as a movement of the polarizing motion mirror, polarizing driving mirror, polarized fishing goggles, etc., in the purchase, you can ask for a clear sunglasses professional use.