The choice of eyeglass lenses should be based on the condition of your own eyes and the diopter. First of all, look at the lens material of glasses, nowadays there are three main materials of glasses lenses, glass, resin and PC lenses. The advantage of glass lenses is good light transmission, not easy to yellowing, cheap, in all the same material, the same degree of lens it is the thinnest, but one of the biggest drawbacks is easy to break, for children, wear glass lenses is very unsuitable, easy to produce debris stabbed eyes, this lens has gradually disappeared in the market. Resin lenses have good light transmission, medium yellowing rate, can be coated with various films, one disadvantage is that resin lenses are thicker than PC lenses and myopic lenses of the same degree, it is not recommended to choose resin for high number of glasses lenses, because resin will look especially thick. PC lenses are also called cosmic lenses, good light transmission, low yellowing rate, high refractive index, the biggest advantage is that they are not easy to become fragments to the eyes after trauma. The most important advantage of PC lenses is that they do not easily turn into fragments and get stuck in the eyes after trauma. The U.S. FDA mandates that children under 18 years old can only wear PC lenses, but PC lenses have the disadvantage of being soft and easy to wear. Secondly, consider the refractive index, if the eye myopia degree in 400 degrees or less, you can choose the refractive index of 1.6 or less lenses, if between 400-800 degrees, you can choose 1.6, 1.65 or even 1.7 refractive index lenses. If the high myopia in more than 800 degrees, it is recommended to choose lenses with a refractive index of 1.74, otherwise lenses with a low refractive index are heavy in quality and will add to the burden of the nasal bridge. Lens surface coating, now there are various coatings on the surface of the lens, anti-blue light, anti-ultraviolet, anti-dust, but there is not much to say. Now the rate of myopia of primary and secondary school students is relatively high, there is a kind of anti-fatigue lenses on the market, the configuration of such lenses need special optometrists with the main sense of optometry carefully examined after the dispensing, if only computerized optometry initial test, can not be used for the dispensing of anti-fatigue progressive lenses.