Do night driving glasses really work?
Yellow lenses reduce the amount of light entering your eye, reducing visibility. These darker colors block more blue light than yellow lenses. But they block more light from entering the eye, reducing visibility even more in low-light conditions. In fact, even yellow lenses reduce overall visible light to some extent because they block some blue light. This can be a good thing during the day, but not at night, when maximum visibility is key. Night driving glasses come in a variety of yellow and amber colors. The darkest lenses filter out the harshest light, but they filter out the largest amount of light, making it difficult to see in dim or dark conditions. Some people who wear night driving glasses say they can see better with them on. However, vision tests have shown that night driving glasses do not improve night vision, nor do they help drivers see pedestrians any faster than they would without glasses.
There are three processes for resin-changing lenses.
The incorporation method, known as bulk polymerization, is similar to the method of glass lens, that is, one or more photochromic dyes are directly incorporated into the polymer monomer of the substrate for bulk polymerization, and the lens formed after curing will change color. Discoloration dye is completely integrated into the resin lens substrate, so the lens made of color persistence is very good.
The uniformity of discoloration and the depth of color after discoloration are highly related to the thickness of the lens. Because the thickness of the lenses at all levels is different, there will be a color difference between the depth of discoloration and the uniformity, and the uneven phenomenon of high brightness is more obvious.
The film type is known as the coating method. It is the chromatic resin lens by coating or dipping in a layer of chromatic dye on the base of the resin lens. Because the coating covers the surface of the lens, the color uniformity is good. The coating, which is only about 0.05mm thick, does not provide enough molecules to make the lens dark enough, so the color is relatively less dark, and the discoloration lasts slightly longer.
Infiltration, known as the penetration method, is to use the principle of penetration, through the thermal diffusion method to make the color dye permeate the surface of the resin lens sheet material, with diffusion depth up to 0.15~0.20mm. The lens has a constant color change characteristic. There will be no inconsistency between the center and the surrounding color as the luminosity gets darker. The color-changing resin lens made by infiltration type has the benefits of uniform color-changing, small color difference, fast and thorough color-fading, which is the mainstream of color-changing technology at present.
What are the benefits of memory metal frames?
Memory metal materials are inherently lighter than metal materials, which can reduce the pressure on the bridge of the nose and skin. The memory metal frame is super elastic, so it never deforms, and it is so apparent that the temples on both sides of the frame line up with the ring. Because the bending can be automatically restored to its original state, the stability is comparatively strong. It has the benefits of high-temperature resistance, corrosion resistance, which will not cause skin allergy, and so on. It is a hypoallergenic lightweight metal for eyeglass frames that is strong and flexible. It is resistant to corrosion, making it proper for people who work, live or play sports in all kinds of outdoor weather conditions. The memory metal can be placed on the side of the face, making it easier and more comfortable to wear. The memory temples can freely rebound 180 degrees without deformation, making up for the insufficient effect of elastic β titanium. This kind of frame is not able to recover due to careless bending, and it has the function of restoring shape itself.
How to choose progressive lenses
The progressive lens can effectively control the deepening of myopia, but there is no reliable empirical evidence. At present, the height of the lens frame is only about 30mm. The distance from the design of the transition interval is not enough, and the comfort of the eye is difficult to adjust the short distance. From the quality and technology, the foreign brand design process is stable and mature, but the price is too high, there are still a lot of people who are not easy to adapt. The parameters of progressive lenses need to be determined by strict optometry.
What characteristics do children's glasses have?
The lens degrees need to change with the degrees of the eye. Because children are still in the process of growth and development, especially preschool children and adolescent children. Preschool is the key period of visual development, and farsightedness is slowly reduced. The eyeball development is close to an adult. Adolescence is the second peak of eyeball development, and myopia is most in this stage and little by little deepens, stopping at the end of adolescence.
Contact lenses or glasses, which is better?
The choice between glasses and contact lenses is a matter of personal preference. Lifestyle, comfort, convenience, budget, and beauty should be all the factors in your decision. Each approach has its pros and cons in terms of vision, ease of use, and eye health. So deciding that if you wear contacts or glasses, and when, is often a matter of personal preference. But Keep in mind that if you wear contacts all day, you should have up-to-date glasses in case you need to stop because of an eye infection or irritation.
Disadvantages of bifocal glasses
The disadvantage of bifocal glasses is that the different areas are clearly spaced and the appearance is not beautiful. The medium distance is fuzzy, and the adaptation period is needed, there is a prismatic jumping phenomenon. The focal distance between the upper and lower lenses is different, with a clear dividing line. The main disadvantage is that when the line of sight moves from far to near, there will be interference like jumping, and the middle distance object image is blurred. Students can adapt to sitting still in a class by wearing bifocal glasses, but they can only wear glasses when they are in class or studying because of the inconvenience and even danger caused by the interruption of the glasses.
