How to Choose Lenses

The lenses are made of glass, resin and pc, and most of them are resin and PC lenses on the market at present. According to the brand, it can be divided into domestic and imported lenses. According to the need, choose a lens with high cost performance. When the brand is the same, judge the price of the lens according to the refractive index of the lens. The higher the refractive index, the higher the price. 

How to choose lenses with correct and appropriate refractive index? Generally speaking, it is suggested that:

Myopia of < 300 or hyperopia of < 200: choose 1.50;300-500 myopia or 200-400 hyperopia: choose 1.56;50-700 myopia or 400-600 hyperopia: choose 1.60;Choose 1.67 below 70-1000;Above 1000, choose glass lens or 1.74 resin sheet. 

If you frequently go in and out of places where the light changes greatly, you may need a pair of intelligent color-changing glasses.