About Plastic Frames
It is usually divided into thermoplastic plastics and thermosetting plastics. Thermoplastics can be reworked under heat. Thermosetting plastics cannot. The plastic frame is usually made of nylon or composite material. Although it is a thermoplastic material, at regular temperature will not become soft. The plastics used to make frames are not always thermoplastic, but they can almost always be softened by heating. Thermosetting plastics are usually used only for small parts.
What is blue light?
Blue light is an important part of natural light, and it is visible light with a wavelength of 400nm-500nm in the spectrum. Blue light can be divided into short-wave blue light (harmful blue light) and long-wave blue light (beneficial blue light). Short-wave blue light harms people’s vision and causes specific diseases, while long-wave blue light helps people maintain normal physiological functions, regulate biological rhythms, and treat specific diseases.
Blue light can be seen everywhere in daily life. In addition to blue light in the sun, electronic products such as TVs, computers, mobile phones, ipads, and LED lights also produce blue light in our daily.
How to protect rimless glasses?
With the continuous improvement of people's living standards, many people begin to pay attention to their quality of life. In the past, many people thought that wearing glasses was for correcting eyesight glasses, but now more and more people use them for decoration, and rimless glasses meet the needs of consumers. Because of its light structure, giving people a sense of fashion, so it is loved by many business people. So how do you protect your rimless glasses?
The Disadvantages of Aspheric Lenses
Here, we will show some disadvantages of aspheric lenses.
The aspheric lens has a relatively small light area. When the eyeball rotates around, it will blur a little when looking at the outside through lens edge. In other words, the visual range of the line of sight becomes smaller.
Human’s eyeball is spherical and the eyeball rotates to the edge. Through aspheric lenses, the objects near the eye appear protruding.
Design principle of progressive multifocal lens
For the same piece of the lens, the top is used to see far, the bottom is used to see close. The upper and lower degrees are different.
There is not a sudden change in the distance degree fixed above the lens to the near degree fixed below the lens, but a gradual transition between the two through gradual changes in refractive power, which has special benefits over common bifocals or trifocal lenses.
Why do nose pads turn green?
Because there are copper accessories in glasses. And the copper and sweat mix for a long time, so it will corrode and rust. The greenness is the mixture of copper salt (copper rust) produced by the copper element in the coating and inorganic salt in sweat and grease dust. The color of copper is green, so is the dirt. If you sweat a lot and the lens bracket is metal, the nasal bracket silica gel is easy to turn green. This is usually due to oxidation caused by the combination of nickel with the natural oils in the skin. Your nose is usually the oily part of your body. The oil in the nose mixes with sweat and then oxidizes the metal. Glass frames are usually made of a kind of copper called Monel. Monel is an easily corroded metal that does not react to many chemicals. It's skin-friendly. The only downside is that it turns green when it rusts.
Why should you clean the eyeglass case?
Although the eyeglasses case is used less, it can not be separated from the glasses. If it is not cleaned for a long time, it will affect appearance and carry a lot of bacteria.