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 ...
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...
1. Different functions
Ordinary sunglasses use the color dyed on the tinted lenses to weaken all the light into the eyes, but all the glare, refracted light and scattered light enter the eyes, whic...
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 ...
The frame, as an important part of the glasses, not only carries the function of supporting the lens, but also an important carrier to show the wearer’s personal taste and style. In the marke...
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...
