Look at the quality of the frame.
Put the glasses flat in front of your eyes, and see if the color of the temples is different in-depth or light under the same light intensity. Sometimes, due to the mistakes in processing, the color asymmetry of the left and right temples will appear.Technology is the quality assurance of the frame, and a frame of fine technology is often reflected in the details.Pay more attention to the welding point near the metal frame to see if there are cracks.
The thermal effect during welding changes the stress structure of the material, or the weld defect, material fatigue, and so on will make it easy to fracture.Attention should be paid to see if the two sides of the stipules of the lens frame are symmetrical and if the fixation is safe.
Why do my glasses hurt the top of my ears?
The problem caused by the angle of the glasses rubbing the ears is mainly caused by the following several conditions. Firstly, it may be that the outer angle is not enough so that the feet of the glasses press the ears too tightly. Secondly, the two sides of the glasses are of different heights. Thirdly, the last situation may be caused by a problem within the angle of depression.
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.
Application of titanium alloy
Titanium alloy is mainly used in aircraft engine compressor parts, followed by rocket, missile, and high-speed aircraft structural parts.By the mid-1960s, titanium and its alloys were already in common industrial use, making electrodes for industrial electrolysis, condensers for power stations, heaters for petroleum refining and seawater desalination, and pollution control devices.Titanium and its alloys have become a kind of corrosion-resistant structural material.In addition, it is used to produce hydrogen storage materials and shape memory alloys.
ROGERS
Wearing glasses equipped with Rogers progressive multi-focus reading glasses can not only avoid the trouble of frequent picking and wearing but become the mainstream of the international reading glasses market with elegant and decent youth. ROGERS' progressive multi-focus glasses have become the bright pearl in the eyes of politicians and business tycoons in developed countries, and thus gradually become popular and popular among the general public. ROGERS's progressive multi-focus reading glasses have won the favor of the reading glasses market and the industry with their excellent cost performance and have become the preferred lens for processing multi-functional reading glasses and progressive multi-focus reading glasses in the industry.
The lenses of prescription glasses
Common materials for lenses include glass, resin, and PC. The glass is fragile and heavy, and few people wear it anymore. PC film is tough and not fragile, but it is not resistant to high temperature and the surface is easily scratched. The most common type of lens on the market today is the resin lens, which is light in weight, hard to break, and reasonable in price. At present, it is generally recommended that you choose resin sheets, and it is recommended that people with ultra-high myopia choose glass sheets.
Generally, lenses can be divided into spherical and aspherical surfaces according to different curvature designs. When choosing, refer to the degree of the eye. For people with lower degrees, There are fewer differences between the two shapes. For people with moderate to high myopia, aspherical lenses will have better imaging effects and clearer vision.
When choosing a lens, a parameter that is often mentioned is the refractive index. Common refractive indexes are 1.56, 1.60, 1.67, and 1.74. With the same degree, the higher the refractive index, the thinner the lens.
Choose clear glasses with the right materials for kids.
A critical point for children to choose frames is to think about the weight, to avoid wearing for a long time, or they will be uncomfortable, unstable, easy to slip. It is recommended to choose an ultra-light plate or TR90 lens frame, which has good chemical properties, good thermal stability, with no deformation, good recovery, and no side effects, lightweight, and convenient material.
