Adults choose the refractive index first and then the Abbe number. Have you ever seen someone who changes their glasses every six months? So eyeglass online hardness is still an important indicator for adults.

Children should first choose the Abbe number and then the refractive index. As children are in the stage of growth and development, they need to maximize the reproduction of real vision, so the Abbe number of children's eyeglasses is more important.

Therefore, it is necessary to choose lenses based on one's situation, and not blindly pursue a high refractive index, which will reduce the clarity of the field of view and give you a comfortable pair of glasses.

We can measure a lens, or even a lens brand, from the perspectives of materials, film layers, optical design, and microstructure! When you want to buy lenses, you can also analyze them from this perspective, which is both intuitive and comprehensive, and there will be unexpected gains!

The Abbe number, weight, impact resistance, UV protection, purity, heat resistance, and background color (whether it turns yellow) that we often pay attention to are closely related to the material of the eyeglasses online cheap lens.

Elderly people use it because with age, the crystalline lens becomes cloudy, and coupled with the degeneration of the rod and cone cells, the scenery they see is significantly different from that of young people, with darker colors.

By prioritizing certain colors that make it easier for people to perceive color differences, controlling the wavelength effectively makes the entire field of view appear more vibrant. By incorporating special pigments into the lens material itself, ideal characteristics are created for each wavelength, making it easy to use in daily life.