What does the Drop Ball Test have to do with the eyewear industry?
FDA mandates that eyewear products must ensure their safety. Impact resistance is a basic norm for binding glasses and/or lenses in the United States. The FDA does say that a drop ball test must be performed on every glass lens for prescription use. The FDA-regulated eyewear products are common in the everyday lives of the public, and the FDA considers impact-resistant lenses to be an important part of the safe design of these devices. Today, safety lenses are rarely mentioned in our sales, but in the 1990s, when resin lenses first entered the Chinese market and glass lenses still dominated the market, safety lenses were a pretty important concept. At the time, the hardening technology has not been upgraded, and the resin lens is easy to wear out than the glass lens. The eyewear industry is relying on lightness, safety (anti-impact), comfort (anti-ultraviolet) step by step to achieve the market share of resin lenses from 1% to 100%.
Characteristics of titanium frames
Titanium is widely used in the eyewear industry because it is not easy to deform, fade and has strong stability. The glasses frame made of titanium can highlight the noble taste and elegant temperament. The glasses frame made of titanium can be divided into pure titanium, titanium alloy, and beta-titanium frame three kinds. To learn about titanium frames, how to identify pure titanium frames?
Titanium frame has the benefits of low density, high strength, good mechanical properties, and strong corrosion resistance. The frame is very light and not easily corroded by moisture. However, due to the poor process performance of titanium alloy, machining is very difficult, the glasses frame made of hydrogen, oxygen, nitrogen, carbon, and other chemical impurities are more absorbed. The wear resistance of titanium alloy is relatively poor, and the production process is relatively complex, so the cost is relatively high and the workmanship is relatively complicated when using this material to make the spectacle frame. The price is much more expensive than the common spectacle frame.
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.
How much do plano lenses cost?
If at big shop downtown, the price of the lens will exceed a hundred, but if you walk the campus store, will be a lot cheaper. Generally is 30-40 at least(not the poor quality, but the price is reasonable for students).UV protection, anti-fatigue, prevention of radiation, computer and television are the basic functions. In the campus store, it is several hundred or so, which can be matched with relatively good quality. Generally, the price of radiation-resistant resin lenses and frames is about 150. If you want to choose a better one, The price can be very high.
Why Are My Progressive Lenses Blurry?
So, why are my progressive lenses blurry on sides? It can be caused by a lot of reasons, and we will list some of them.
The strength of progressive lenses is the factor that leads to initial peripheral blurriness. Progressive lenses tend to be blurry on the sides because each lens promotes three fields of vision. In addition, peripheral blurriness or haziness is a sensation that typically develops because more than one lens has been incorporated into one lens. The wearer also might feel as if he or she is moving from side to side.
After learning what may cause progressive lenses blurred, so how can you adapt to the progressive lenses? Therefore, in the following section, we will show you how to get used to progressive lenses.
Phone can identify polarized sunglasses.
Take a mobile phone with an LCD screen, turn it to maximum brightness, and look at the LCD screen through the lenses. Make sure the lenses are parallel to the display, and then slowly rotate the phone. When the true polarized lens is rotated at a certain angle, the light from the display becomes obviously darker, or even pitch-black. If they're not dark, they're not polarized sunglasses.
Disadvantages of progressive lenses
Wearing progressive multifocal glasses for the first time may cause slight dizziness and shaking when walking. Be careful when moving up the stairs. The perception of space changes, the perception of the distance of the object, and the perception of depth have changed. New wearers should not drive immediately and do vigorous exercise. When you look close, you need to turn your eyes down, and your eyes are mildly uncomfortable. Seeing the object through the blurred vision area around the lens, the object becomes blurred. Therefore, when new wearers look at things, turn their heads more, turn their eyes less, try to use the far-distance zone, the near-distance zone, and the middle-distance zone to see the object.