Why does shape memory alloy have memory ability?
It starts with its microstructure. When a metal is solid, its atoms are always arranged in a regular way, forming a lattice. Under different conditions, such as temperature, metal may have a different structure, in which case it is said to be in a different phase. The change from one phase to another is called a phase transition. The properties of a metal change during a phase transition. The temperature at which a metal transforms is called the transition temperature. The difference between a shape memory alloy and other metals is that the phase transformation process in a shape memory alloy is reversible under certain conditions.
The Role of Fishing Sunglasses
The special effect of the polarized lens is to effectively eliminate and filter the scattered light from the beam. In general, a polarized lens can arrange all the light in the same direction, so that the visual field is clear and natural. It also blocks ultraviolet light, reducing damage to the eyes and clearing out blinding light. Fishing glasses have the function of polarized light, so they can block all harmful light without affecting the transmission of visible light, which can really achieve the function of eye protection. In addition to the basic anti-ultraviolet function, fishing glasses also have the functions of anti-glare, reducing pavement reflection light and water scale light, etc., suitable for driving, fishing, tourism, and daily wear.
About the early domestic anti-reflection coating lens
Chinese coated lenses appeared in the mid-1980s. At that time, Europe (such as France and Germany) and Asia (such as Japan, Singapore, and Taiwan) had already launched coated lenses to the market, and the grade of lenses was evaluated based on the quality of the anti-reflection effect. Among them, Germany and France were the two leading countries in technology. Technically, the use of French original film material (referred to as H2) can reduce the effect by 99.98% (refers to the light transmittance, the same below). Almost you can not see the reflection, but the material is expensive. Therefore, the coating lens which is currently used in the world is born. The anti-reflection effect is controlled at about 98%, so the coating cost is greatly reduced. And it is accepted by consumers because it presents various colors, especially green. At the same time, because at the same time, it can be easily distinguished from non-coated lenses. It can reflect the high-grade film lens, and it is accepted by the sales staff.
Is it true that green film prevents blue light?
Some lenses filter out harmful blue light by reflective multiplayer coating. The lens has a bright blue-violet coating. Green film anti-blue lens relies on the lens material itself to absorb blue light. Therefore, it is impossible to know if the lens can really block the blue light only by looking at the film layer. Instead, it is necessary to use the test equipment of blue light blocking rate or ask the manufacturer to provide relevant experimental data. There is no problem wearing an anti-blue lens unless the user has a high demand for color authenticity, like painters, graphic designers, etc. Because when using anti-blue glasses to see white blue objects, there will be a certain color deviation. It is up to the above workers to make their own decisions.
Why were eyeglasses invented?
Glasses are commonly used for vision correction, such as reading glasses and myopia glasses, but they are sometimes used for cosmetic purposes if special lenses are not available. Safety glasses provide eye protection for a construction worker or laboratory technician against flying debris. They provide protection against visible and near-visible light or radiation. Sunglasses can improve vision in bright sunlight and can protect your eyes from excessive UV damage. Special glasses can be used to view specific visual information. Sometimes glasses are used purely for fashion or aesthetic purposes. Even eyeglasses used to correct vision come in different kinds of styles, with frames made of plastic, metal, wire, and other materials.
How to choose blue light blocking glasses?
Nowadays, electronic products such as mobile phones and computers have become indispensable tools in our lives. While these high-tech products bring us convenience and fun, they also bring symptoms such as eye fatigue and myopia. Subsequently, blue light blocking glasses have also received everyone's attention. Anti-blue glasses are only suitable for people who use electronic products for a long time, not for people who are visually fatigued. Exposure to such unnaturally strong blue light for a long time every day, especially for teenagers and children, needs to pay more attention to the prevention of blue light. So, how to choose suitable blue light blocking glasses for kids?
Anti-blue light is necessary, but not all blue light can be filtered out, because blue light will interfere with the body's melatonin secretion after being over-filtered, thereby affecting sleep. Therefore, when choosing blue light blocking glasses, you should choose appropriately according to your own eyes.
For how to choose anti-blue glasses, consumers can distinguish from the color of the lenses. Generally speaking, a lens with a yellow color will have the effect of blocking blue light. But too dark lenses will affect the contrast sensitivity. Therefore, it is recommended that consumers choose moderately. In addition, consumers should also pay attention to whether the glasses products (lenses, frames) have conformity marks, etc. It is best to choose professional and well-known glasses shops to match glasses.
The Pros of Rimless Glasses
First, rimless glasses are light weight. Compared with other glasses frames, they are much more lightweight and greatly ease the pressure on the bridge of nose and eyes. So, it is suitable for those people who have strong prescriptions. As we know, the stronger prescription is, the heavier glasses are. So, no frame glasses would be a good choice.
Second, rimless glasses are fashionable. They make you look elegant and sophisticated.
Third, when you wear rimless glasses, there will be no restrictions or limits when it comes to the size of your lenses or the shape of your lenses. You may be surprised at all the options you will have when you make the decision to wear rimless glasses.
Meanwhile, besides the advantages of rimless glasses, there are some negative voices of frameless glasses.
