In the discussion of “What is the optical refractive index of an eye lens?” When it comes to this problem, we first need to understand the physical concept of optical refractive index, ...
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 ...
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...
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...
Beautiful eyes are an effective “weapon” for hunting the heterosexual. Women in the new era, and even men who are at the forefront of developing trends, already have a great need for ...
