Relevant standard
Ultraviolet protection factor (UPF)
Definition: UPF is a measure of the ability of a fabric or material to block ultraviolet light, and in the case of sunglasses, it reflects the ...
Polarizers are manufactured according to the principle of polarization of light. We know that when the sun shines on the road or water, it directly irritates the eyes, making the eyes feel...
Choose the right product
Uv protection function: UV damage to children’s eyes is greater, to choose sunglasses that can effectively block UV, the label is usually marked with UV400 and other ...
In the discussion “Can nearsighted people not wear glasses?” On this topic, we first need to clarify the definition of myopia, the causes and the role of glasses in correcting vision, a...
Effect of refractive index on visual acuity in the aged
Lens thickness
For the elderly with high myopia or farsightedness, it is more appropriate to choose a lens with a high refractive index. The ...
1. Nose pads
Different from adults, children’s heads, especially the angle of the nose peak and the curvature of the bridge of the nose, have more obvious differences. Most children have...
