Views:120 Author:Site Editor Publish Time: 2021-01-08 Origin:Site
Optical glasses are a general term for glasses developed by using optical principles. Common ideal optics frames include concave lenses, convex lenses, prisms, and some common contact lenses. These kinds of glasses are what we often call optical glasses. Different optical glasses have their own scope of use. These optical glasses have a very important role in the scope of their own use. They have a very important role in correcting human vision, protecting the health of human eyes, and treating people's eye diseases.
Optical reading glasses are a type of optical products used for people with presbyopia. They are convex lenses.
Reading optical glasses are used to supplement vision for middle-aged and elderly people. Like myopia glasses, they have optical indicators specified in many national standards and some special rules of use. The use of reading glasses plays an indispensable role in improving people's quality of life.
There are three main types of reading glasses in the market, namely single vision lens, double vision lens and progressive multifocal lens. The single vision lens can only be used to look close, and the glasses need to be removed when looking far. The double vision lens refer to the upper half lens used to look far, and the lower half lens used to look close, but this kind of reading glasses has the phenomenon of jumping and the appearance is not beautiful. Progressive multifocal lenses can meet the needs of viewing objects at different distances in the distance, middle and near, and the appearance is also very good.
Bifocal optical glasses: The lens with two focal points is equivalent to two lenses combined together. Generally, one lens looks far and the other lens looks close. People with myopia often need to wear bifocal glasses after having presbyopia. The upper and lower dioptric powers of the lens are different. Look at distant objects through the upper part, and read and do near work through the lower part. In addition to presbyopia, some people work at close range for a long time, in order to reduce eye fatigue, they also need bifocal glasses. There are also bifocal glasses for children to prevent the development of myopia.
The photochromic optical glasses is a lens that becomes dark when exposed to light of a certain wavelength (usually ultraviolet light), and when it is no longer illuminated by this light source, it will return the original light transmittance and be clear. The photochromic lens can be made of glass or plastic including polycarbonate. The discoloration effect is caused by silver chloride or other halides added to the lens. Such substances are transparent to visible light when they are not irradiated with ultraviolet light. When they are irradiated with ultraviolet light, they will react chemically. After the chemical reaction, it will absorb part of the visible light and make the lens appear dark. This chemical reaction is a reversible reaction, so the lens will return to its original transparent state when it is no longer exposed to ultraviolet light.
Optical glasses also have other functions, such as anti-ultraviolet, anti-glare, anti-scratch, etc., so you will find uv protection optical glasses, anti reflective optical glasses, etc. in the market
1) Single vision lens is the lens type that are most common and easy to adapt. Aspheric design should be selected in optical glasses design.
2) Multifocal lenses, suitable for people who are older and the eye adjustment ability has reduced.
3) There is a smooth transition between the eye areas of the progressive lens, and there is no image jumping problem. A variety of design methods need to be used to balance the size of the available area for near and far and the wearing comfort. The choice of optical glasses should be based on your own real wearing experience.