- Basic requirements for sunglasses
Block 99-100% UVA and UVB;
Filtering 75-90% of visible light;
Absorbs UV light without causing distortion and distortion
- Don't be misled by fake UV filter signs
(100% UV absorption on the lens or UV400). To ensure that these labels are true, it is best to buy sunglasses in a store that can detect the UV filtering performance of the lens, or buy it from regular channels.
- The color of the lens is uniform and a certain area will not be darkened
If it is a gradient lens, the lens color should be gradually lighter from top to bottom. Sunglasses worn while driving should be gray (gray, smoky, gray-green) so that it does not affect the color of the traffic lights.
- Ensure that the lens does not produce distortion
Hold the sunglasses, straighten your arms, and look at the right angle or straight line (such as the door frame, window) through the lens. Slowly move the frame, up and down, if there is distortion, skew, or bending, this indicates that the object is distorted, the lens has optical defects, and it is unqualified.
- Make sure the lens blocks enough visible light
Try on the mirror. If you can easily see your eyes through the lens, the color of the pair of sunglasses is not dark enough. Note: This method does not apply to color-changing lenses.
- The weight of the sunglasses is evenly distributed on the nose and ears.
Carefully adjust the curvature of the frame and the position of the nose pad. The frame does not clip the bridge of the nose and does not grind the ears. When worn, the eyelashes do not touch the frame.