Usually 500 degree myopia patients with 1.61 and 1.67 refractive index lenses can, the difference between the two clarity is not much, the difference is mainly thickness and price. With 1.61 lenses, the lenses will be thicker than 1.67 lenses, and the price is usually slightly cheaper. If you choose 1.67 lenses, the price should be higher than 1.61 lenses, but the thickness of the lenses is slightly thinner and the comfort of use may be better. Usually the difference in clarity between 1.61 and 1.67 refractive index lenses is not significant, but the choice should be based on the actual situation of the patient. Usually the higher the myopia, the higher the refractive index of the lens should be. Common lens materials on the market include glass, resin, etc. The former has a relatively strong refractive power, but is fragile and usually only used for super high myopia. In contrast, resin lenses are not fragile and are more often used, and the price is relatively lower than glass lenses, but they are easy to scratch, easy to deform, etc. If the myopia is exactly 500 degrees and has not yet reached the standard of high myopia, you can choose the lens material according to your needs. In addition, myopic patients to match glasses, must go to professional institutions for scientific optometry, do not cause inaccurate measurement, aggravate myopia, etc. 500 degrees of myopia patients, whether you choose 1.61 refractive index lenses, or choose 1.67 lenses, prescription lenses should be worn at the right time when using the eyes. If you use your eyes without glasses for a long time, it may lead to a deepening of myopia.