What are bifocals?
A bifocal lens is a lens with two focal points. Because of the imaging principle of the lens, even half of the lens can still present a complete image, and the two images do not interfere with each other. In the past, both short-sighted glasses and presbyopia glasses were called single-focal lenses, which had only one focus. Later it developed to the bifocal lens, and the same lens is divided into upper and lower two parts. The upper part of that lens is used when seeing far, and you look down when seeing close objects, just the reading distance, naturally used the second half.
Single Vision vs Progressive: What Are Their Differences
With single vision lenses, you can also just use the center of the lenses to avoid prismatic effects if your prescriptions are very unequal for both eyes.
As for progressive vs single vision, they also have differences in frame selection. You will stick to frames when choosing progressive lenses that will provide you with a minimum height of 14mm from the point you are looking through the lenses into the distance to the point you are looking down while you read.
Besides the above differences, they are also some other differences between single vision glasses and progressive lenses. You can choose either one based on your needs. To choose glasses, Koalaeye glasses are recommended. They come in stylish and at a cheap price.
Glasses with metal frames.
This is a very popular style of glasses. The feature of the glasses is that they look classic and retro, but when worn with modern clothes, they will make people feel bright.
The first feeling given by metal frames is retro, indeed, no matter what kind of metal frame is worn, there is always a kind of old retro flavor. But metal frames aren't just retro for anymore. Now, the metal glasses frame is synonymous with the avant-garde.
Sports goggles
With the improvement of people's sports concept and sports protection concept, sports goggles are also widely welcomed. Safety glasses are worn during sports must have four major functions, safety (PC lenses), protection (TR-90 frame, soft and flexible), comfortable (non-slip nose pads and foot covers), and beauty (match sports and leisure clothing).
Sports goggles with shatter-resistant plastic lenses and side shields can prevent balls or sand from hitting the eyes. It can be fixed on the head without worrying about falling off during intense movements. The unique design of the rim of the frame makes the glasses very close to the human face and has a proper external isolation effect so that the human eye is not easy to be attacked by bacteria. The special lens has the functions of anti-fog, anti-shock, and ultraviolet rays, which is very suitable for outdoor activities.
How Prescription Computer Glasses Work?
Ordinary glasses and radiation-proof screens don't filter out high-energy short-wave blue light, which is most harmful to the eyes. Prescription computer glasses can eliminate the eye potential fever, headache, fatigue, dryness, and other adverse symptoms caused by electromagnetic radiation. It has different penetration and absorption functions to different light and can resist reflection and strong light, and the user feels clear and natural vision after wearing it. Prescription computer glasses can significantly reduce eye strain, prevent headaches and reduce neck/shoulder back fatigue because computer prescription lenses are designed to help you focus your position in the middle area of your computer screen so that the entire lens provides a clear view of your computer screen. These specialized prescription glasses will provide the most comfortable view of your computer screen, as the entire lens is dedicated to providing a clear vision for your middle area.
About industrial pure titanium
For the industrial pure titanium, titanium content is not less than 98%, containing a small amount of oxygen, nitrogen, hydrogen, carbon, silicon, and iron impurities such as dense metal. The labels are TA1,TA2,TA3,TA4. It's arranged by more and more impurities. The TA1 titanium content is more than 99.5%, and the price is not high. But no matter which links, for molding, welding, polishing, processing difficulty is very great.The price of almost all titanium alloys in the national standard is higher than that of pure titanium.
In reality, the price of β titanium is higher than pure titanium. Pure titanium is almost no elastic, but β titanium is not only elastic, and has the advantages of ultra-light corrosion resistance. β titanium does not have a specific composition. Memory titanium can cost tens or even tens of times as much as pure titanium.
Using memory alloy to make glasses frame is the use of its superelastic characteristics at a certain temperature (elasticity is several times that of stainless steel) and did not use its memory function. Compared to beta-titanium, memory titanium is so difficult to process. It is so elastic that shaping is difficult and impossible at room temperature, and memory titanium heat treatment is another difficult and even secret process.
When should I use blue light glasses?
Most of us spend a few hours a day in front of a screen. Because so many people work on a computer all day, many people wear blue glasses in the office. At the same time, many American high school and college students spend hours a day on their computers and could benefit from blue light glasses.
