1. Natural materials: The most commonly used crystal lenses are polished from quartz ore. The main component is silicon dioxide (SiO2), and pure crystal contains SiO299.99%.

　　Classification:

　　Colorless: SiO2 has high purity.

　　Tea (Citrine): It shows a different color due to other elements, which can reduce the transmittance of visible light and make the person who is photophobic wear comfortable, so there is a sense of nourishment .

　　 Advantages: The material has high hardness and is not easy to wear.

　　 Disadvantage: Cannot fully absorb short-wave ultraviolet rays.

　　 cannot reduce the transmittance of infrared rays. The dense optical lens of the material is not uniform, and those with impurities will have stripes and bubbles, which will cause birefringence and affect vision. Rare and hard to find, expensive.

　　2. Glass lens: The glass lens suitable for making lenses is optical glass, and the quality requirements are particularly strict.

　　 such as: refractive index, dispersion, transmittance, etc. The main component is silicon dioxide (SiO2), followed by boron trioxide (B2O3) and phosphorus pentoxide (P2O5).

　　 Advantages: Good hardness, not worse than crystal.

　　 can be colored after being mixed with various oxides, which can reduce strong light stimulation and can also absorb harmful rays such as the outer line of purple optical lenses and infrared rays. 300 years of history).

　　 Disadvantages: heavy weight, the specific gravity is twice that of resin materials. As the refractive index increases, the specific gravity increases significantly, which makes wearing uncomfortable.

　　The impact resistance is poor, and mechanical damage can easily cause damage to the glasses. Therefore, the safety is poor, and people have been looking for better alternative materials for nearly a hundred years.

　　How to daily maintain eyeglass lenses

　　There are many types of lenses, such as glass, resin, and PC lenses, depending on the material. Different performance is different. In order to maintain the lenses, the focusing lens must first have a more comprehensive understanding of the performance of various lenses:

　　 Safety: The glass sheet is fragile, and the resin sheet is not easy. Broken, PC tablets have strong impact resistance.

　　Abrasion resistance: The glass sheet is the most wear-resistant, and the surface of the coated spectacle lens is coated with a multi-layer dielectric film. Its function is to reduce reflection, reduce interference light, and reduce dispersion. It reduces the circle feeling of high-level lenses and has a good optical effect. But the added diaphragm is the least wear-resistant, and the hardened resin and PC white film are more wear-resistant than the added diaphragm.

　　Thickness: ordinary resin sheet is very thick, glass sheet is thicker, middle-fold resin sheet is thinner, PC film and high-fold resin sheet are thinner aspherical lens, high-fold glass sheet Thinnest. The higher the degree of myopia lens, the thicker the edge, the larger the frame, the thicker the spectacle lens.

　　The maintenance of various lenses:

　　The glass can be wiped dry with lens cloth or facial tissue;

　　Resin sheet and PC sheet should be washed with water and then use a soft lens cloth or facial tissue to gently absorb the water stains;

　　Dry wipes and repeated wipes like glass, should minimize the number of wipes, and the maintenance of the membrane should be washed with water to remove the surface sand and dust. If there is oil, it can be removed with a neutral detergent. After washing, use it to clean and soft. The mirror cloth or facial tissues gently soak up the water stains.