The material of the eyeglass online lens is an important factor in measuring the quality of the lens. Simply put, the higher the refractive index of a lens, the thinner it will be, and of course, the more expensive it will be.

Generally speaking, the higher the degree of myopia, the thicker the edge of the lens. Therefore, considering aesthetics, if you want to make the lens thinner, you need to consider the refractive index factor. However, high refractive index lenses have lower Abbe numbers, and the imaging effect is not very good.

Abbe number is an optical term that represents the dispersion coefficient of light. The higher the coefficient, the smaller the dispersion and the better the imaging.

Transmission ratio refers to the ratio of the total amount of light entering the eye after passing through the eyeglasses online cheap lens to the total amount of light reaching the lens. Simply put, transmittance refers to the clarity of the lens, and the higher the transmittance value, the better the transmittance performance and clarity.

The film layer of a lens is its clothing. After multi-layer coating processing, the lens not only greatly improves its optical properties such as light transmittance, but also its hardness, wear resistance, and durability. From the inside out, it can be divided into reinforcement film, anti-reflection film, and top film. Good discount eyeglasses online lenses have coating technology, providing you with a clear and authentic perspective.

Strengthening film, also known as hardening layer, after coating, has characteristics such as high hardness, high adhesion, and high transparency, which can effectively improve the wear resistance of lenses, prevent film detachment and yellowing, and enhance the service life of lenses. The anti-reflective film mainly utilizes the principle of light interference to reduce or eliminate reflected light, significantly enhancing the transmittance of the lens.