Knowledge of lens
Refractive index: The higher the refractive index, the thinner the lens. The thicker the original lens, the greater the benefits brought by the high refractive index.
Abbe number: If the Abbe number is low, when looking at high-light areas such as point light sources at higher degrees, dispersion (rainbow fringes) is likely to occur in the edge area of the vision-ps: Generally speaking, the higher the refractive index , The lower the Abbe number, so it is not blindly pursuing high refractive index!
Density: The lower the density, the clearer the lens will be. This is generally not a problem if you don't choose glass material.
Impact resistance: good impact resistance is that it can protect the eyes, and the second is that it can be made thinner
Thermal stability: Don't put your glasses in the car to expose to the sun. The MR series is sun-resistant, second only to PC
Wear resistance: Nowadays lenses must be coated, so the wear resistance is determined by the film layer rather than the material of the lens itself
