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.
Disadvantages of contact lenses
They require more care than glasses. If you don't clean your contact lenses properly, or if you don't wash your hands before touching them, you could get a serious eye infection. Wearing contaminated contact lenses not only causes damage to your eyes but causes inflammation. If you have high astigmatism, your vision may become blurry when the lenses rotate. And there are a lot of contact lens health risks. There is a lot of news exposed that many informal manufacturers use fake or shoddy materials to make contact lenses, especially for the so-called beautiful contact lens, there are more risks in dyeing and health. The damage to the eyes is unimaginable.
Square face with round glasses
The square face belongs to the type of facial lines or tough, which looks a bit unnatural. For this type of face, it is best to choose round glasses because a round shape can make your facial lines softer and add a little femininity. The most suitable glasses for a square face are round, but the size of this round is also very particular. If you have a wider face, it is better to choose larger glasses, which can better modify the face and make the face smaller.
Choose the cost-effective glasses.
Choose your favorite glasses online. Open the shopping website, and select a store with high credibility. Choose your favorite glasses according to the style, lens, frame color, blue light blocking, radiation protection, and other factors, and then communicate with the customer service about the thickness of the lens and other specific details. If you see the frame is not suitable for yourself, you can communicate with customer service ahead of time to see whether you can buy the frame to send freight insurance. If it is not suitable, can we return it for a refund? To buy a store with a high reputation, you can look at the store's good comments and bad reviews. Talk to customer service. Sometimes there are hidden discounts.
How do bifocal reading glasses work?
Bifocal reading glasses have two different lenses on the same lens. The top of the lens is your normal distance prescription, while the bottom is for close-up viewings, like reading. The two lenses allow you to alternate between them by moving your eyes up and down as needed. A bifocal lens is a type of lens that has two different areas of vision: one for close range and one for long-range. Typically, the upper section covers remote vision and the lower section covers reading. With a traditional bifocal lens, you can see the difference between the two lenses because the lower curve is a little different.
Put into the lens box when not in use.
When taking off glasses, many people will easily hang them on the head, collar, or casual display, so that glasses often suffer a variety of damage. To do this, fold the glasses and place them face up in the case. Do not place your glasses in direct sunlight or in high temperatures, as heat can easily peel off the film on the lens. For example, in summer, the glasses are exposed to direct sunlight in the car for a long time, which is easy to cause lens stripping.
Choose a good frame material
Each pair of glasses has its own characteristics and highlights. The frame itself is an ornament, playing the role of beautification. Today's plate spectacle frames are particularly popular with all kinds of people. Work is complicated and delicate, and design is diverse. Importantly, color and luster are good, not allergic. And it doesn't fade. It is also a high-grade frame. Both the grade and the design are very advantageous. Many brand glasses are made of plates. Some are made of high-grade plates. The appearance is beautiful and stylish.