What is a qualified plano lens?
First, identify the surface. High-quality products should not have obvious scratches, pitting, edge collapse, sand holes, water ripples, bubbles, and other surface defects. Put glasses next to the place of 33 cm or so at the moment. When looking at the object through glasses, there is no phenomenon that the objects become big or decrescent, and you should not have a feeling that the objects are beating. Otherwise, the quality of the glasses has a problem. Next check through the instrument identification. Finally, check whether the trademark, manufacturer, and quality certificate are true and reliable. The lens of the international famous brand product is often engraved with the manufacturer's trademark, which can be found by careful observation on the edge of the lens.
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.
Plate Frame
Glasses processed with acetate sheets become sheet frames. The plate frame is not easy to burn, the specific gravity is small, and the base arc is not irradiated by ultraviolet rays to change color. In addition, it has high hardness, good gloss, and durability, but it is not easy to bake and the temperature is 115-130 degrees. The style is more beautiful, and it is not easy to deform after wearing. The current market is that the plate frame combines the thickness of the plate and the metal texture, and combines different types of lenses to create fashion and personality. There are not only retro-style frames, but also popular frames, combining a variety of elements to create classic glasses frames. Its workmanship has undergone complex processes such as turning, grinding, and polishing, so it is relatively high-end.
The best frame is the one that suits you.
You can choose the full-frame, because the edge of the lens is relatively thick, which can block the thickness of the edge, so it is suitable for high myopia to choose. They can choose a smaller frame. The size of the eyeglass frame should match the pupil distance so that the edge thickness of the lens is thinner and they are more comfortable to wear. The size of the frame should be proportional to the size of the face. The upper edge of the frame should not be higher than the eyebrow and the eyebrow should not be visible in the lenses. The shape of the frame should match the face shape and skin tone to meet aesthetic requirements. Everyone's face size is different, so the smaller the frame is, the better, based on what fits you and what you like.
Do clear frames make you look older?
Men wearing clear frame glasses don't look old if the choice suits their own frame is good. Although it is often said that round faces are better for angular frames, while a solid face is better for rounded frames. But you can't generalize about face shape and frame. The best way is to go to the store to pick up the style of the frame to try on. Make comparisons before making a decision. The clear glasses frame style is very unique, if you like, you can try.
The discoloration principle of photochromic lenses
The fine grains of silver halide and copper oxide were melted into the glass melt of the lens blank material to produce the lens. When the lens is in the ultraviolet environment, the silver halide molecules will undergo a chemical reaction due to the ultraviolet radiation and decompose into silver ion particles and halogens. Because the silver particles are dark and absorb visible light, the lens gets darker. When the ultraviolet light is weakened or isolated, silver ions and halogens are recombined under the action of catalyst copper oxide to form silver halide, so the color of the lens gradually becomes lighter and transparent again. The discoloration mechanism of the resin lens is similar to that of the glass lens.
How long does it take to get used to progressive lenses?
Because the adjustment of each eye is different, so there will be some differences in the adaptation period. It usually takes about two weeks to get used to it. Probably many young people are familiar with this kind of lens, so they adapt to them for only a week or so and can restore the normal visual effect. If it's been two weeks and you still feel that you can't see clearly, or you have the feeling of nausea, etc., then you need to test and adjust. You need to go to the hospital to see the specific case, to find out whether it is a quality problem of the sunglasses, or there are some artificial reasons. If there is a problem, we should also replace the lenses in time, otherwise, it may lead to the problem of visual fatigue. Therefore, it is still necessary to promptly confirm the case of optometry, and then replace the appropriate glasses.
