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 ...
Choose the right sunglasses
Uv protection: To ensure that sunglasses can effectively block ultraviolet light, the label is usually marked with UV400 and other signs, indicating that it can block mo...
Choosing the optical lens material suitable for the elderly requires comprehensive consideration of the elderly’s eye needs, physical conditions and living habits. The following is a specific...
Common eyeglass frame materials include metal, plastic, cellulose acetate, composite materials, etc.
1. Metal materials
Metal eyeglass frames mainly include stainless steel, titanium, aluminum-magn...
What is cellulose acetate?
Cellulose acetate refers to a thermoplastic resin obtained by esterification with acetic acid as a solvent and acetic anhydride as an acetylating agent under the action o...
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...