A brief talk on the classification and function of optical lenses

Optical glass refers to glass that can change the propagation direction of light and change the relative spectral distribution of ultraviolet, visible or infrared light. It is a lens made of optical glass. The definition of optical glass is glass that has specific requirements for optical properties such as refractive index, dispersion, transmittance, spectral transmittance and light absorption, and has uniform optical properties. There are two main types of telescope lens: glass and resin. The glass sheet has high hardness and is heavy and fragile; the resin sheet has strong light transmittance, light weight and is not easy to break, and can protect against ultraviolet rays, but has poor wear resistance. The thickness of the lens depends on the power and refractive index. The center of the lens is thin and the periphery is thick for myopia, and the opposite for hyperopia. The higher the degree, the thicker the lens, and the higher the refractive index, the thinner the lens. People with high refractive error choose high refractive index lenses. After many people wear glasses, they tend to wear them all the time until they are broken or unusable.

In fact, if the lenses are "out of service", it is likely to lead to accelerated myopia, and most spectacle wearers know very little about this. Therefore, ordinary myopic patients should generally replace their glasses every two years, one is to adjust the degree, and the other is to "replace". Once the mirror surface of glasses is scratched, it will obviously affect its optical correction performance, so it is necessary to maintain and check the glasses regularly, and update them in time to keep them in good working condition. Teenagers whose degrees change rapidly should try to change their glasses every six months to a year. Adolescents are at the peak of eye use. Due to long-term close eye use, ciliary muscle spasm will occur, and myopia is particularly easy to deepen. Teenagers who overuse their eyes need to undergo optometry once every six months. If the glasses are no longer suitable for the changes in the diopter of myopic eyes, they should change them in time.

Use resin glasses to regularly clean the spectacle lenses to maintain better clarity. When cleaning, do not use paper towel or lens cloth to wipe directly, but rinse with water first. If it is stained with grease, it can be cleaned with detergent or neutral soap, and then washed with water, then dry naturally, or use a soft lens cloth. Gently wipe off the water, try not to rub the glasses directly when wiping the water, and avoid scratching with sharp objects. The light transmittance and mechanical and chemical properties of optical lenses are relatively good, with constant refractive index and stable physical and chemical properties. Optical lenses have superior properties and high refractive index.