Choosing eyeglass lenses is mainly based on the needs of your work and life and the environment in which the glasses are used, and the performance of the glasses should be selected. In addition to the corrected visual acuity of the glasses, the distance used, and the degree of glasses, different performance characteristics of different lenses should also be considered. The color of the lenses The lenses should be clear and colorless for jobs with high and stable visual requirements for vision, color and distance, such as students, car drivers, surgeons, artists, etc. If a car driver wears a heavily colored lens, he/she will be insensitive to distance changes and will not be able to judge the distance accurately and will be prone to accidents. Shape of the lenses The shape of the lenses is chosen after the frame is selected. Transmission of lenses Optical lenses with multi-layer anti-reflective film, colorless optical lenses and aspheric ultra-thin optical glasses lenses have better transmission. The thickness of the lenses is related to the size of the refractive index of the lenses, to the size and shape of the frames, to the size of the pupil distance and the amount of the shifted optical center, to the axis of astigmatism, and to the nature of the lenses (concave and convex). The weight of the lens is related to the lens material, glass lenses are heavier than resin lenses. The same lens material is heavier than the one with smaller specific gravity and heavier than the one with smaller volume (related to the lens prescription and shape size). Hardness of the lenses Glass lenses are harder than resin lenses and are more wear-resistant. Strength of the lenses Resin lenses are stronger than glass lenses, impact resistant and not fragile Special functions of the lenses such as anti-UV, anti-electromagnetic radiation, anti-infrared, high temperature, oil, acid and alkali, anti-dispersion, anti-deformation (ultra-thin aspheric lenses), anti-brightness, etc. Such as electric and gas welding lenses, computer lenses, underwater lenses, fishing lenses are different.