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.
Common Problems with Varifocal Glasses
In this section, we will list some common problems with varifocal glasses. The most common problem with varifocal glasses is people being unable to focus on what they need to. Losing focus often leads to some discomforts such as headaches or dizziness when performing tasks that require quick changes in near and middle-distance focus.
Besides, some people also experience a sort of swimming feeling when they are walking. It may be caused by being very aware of the distortions in your peripheral vision as well as the reading portion at the lower part of the lenses.
So, how to use varifocal glasses? The best way is to keep yourself from looking downward as you walk. You may also experience soft focus at the edges of the lenses and need to move your head more to see near objects better.
What frames can you choose?
According to its style, the spectacle frame can be divided into full frame, half frame, no frame, and eyebrow frame, combination frame, etc. They each have their own characteristics, but have their own loyal fans, and give users more choice. It is recommended that consumers who like broad vision and light frames choose rimless or half-frame glasses. The young and fashionable people choose the ever-changing full-frame frames. There are also people who like ornamented frames, such as print flow pattern small carving, and so on, and these details on the treatment of different styles of glasses frames have the icing on the cake.
Professional glasses repair service
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What are the causes of lens damage?
When the force area of the lens is small, the impact resistance of the lens is worse. When subjected to the impact of external forces, the lens will naturally be squeezed and cause breakage.
In particular, some lenses with low degrees and high refractive index are possible to cause this phenomenon. When the frame fell from a height due to wrong placement, there is a collision between the edge of the lens and the ground or hard objects. It will produce a broken or collapsed edge. In the process of the lens falling from high, the impact force is larger, and the stress point is smaller. When the glasses are falling, the upper edge of the lens, the convex groove of the upper frame, squeezes against the lens. The middle part of the upper half is easy to cause edge collapse. In the process of processing the template, the template is not accurate, so that the glasses side and the frame can not be uniform fusion, and the force of the lens is uneven. It will be easy to lead to greater stress in some parts, resulting in edge collapse.
What Is Polycarbonate Lens?
Polycarbonate was invented in the 1970s for aerospace applications and is currently used for the helmet visors of astronauts and for space shuttle windshields.
Polycarbonate lenses were introduced in the early 1980s in response to a demand for lightweight, impact-resistance lenses. Since then, polycarbonate glasses have become standard for safety glasses, sports goggles, and children’s eyewear.
Polycarbonate glasses come with a lot of features such as thin and light and they provide 100% percent UV protection and are up to 10 times more impact-resistance than plastic pr glasses lenses.
What is the progressive multifocal lens?
The lens of progressive multifocal glasses can change the refraction of the lens at the upper part of the central channel of the line of sight, which can effectively solve the difference of refraction when people view objects at different distances from long, medium, and short distances. Depending on demand, people have the flexibility to change or compensate vision according to visual distance, making it easier to help to adjust your vision in a variety of situations.
