What are the origins of saddle bridge glasses?
Rimless glasses were introduced in 1880 and were popular until the 1950s. Rimless glasses made in 1880 and 1920 lacked a nose pad. Instead, they use a saddle bridge, so they were sometimes called saddle bridge glasses. Horses are the main means of transportation. Early rimless saddle glasses were designed to be close to the face. Rimless glasses with nose pads were introduced in 1921. The nose pad keeps the glasses farther away from the face. In addition, frames can be made much larger.
What is a qualified plano lens?
First, identify the surface. High-quality products should not have obvious scratches, pitting, edge collapse, sand holes, water ripples, bubbles, and other surface defects. Put glasses next to the place of 33 cm or so at the moment. When looking at the object through glasses, there is no phenomenon that the objects become big or decrescent, and you should not have a feeling that the objects are beating. Otherwise, the quality of the glasses has a problem. Next check through the instrument identification. Finally, check whether the trademark, manufacturer, and quality certificate are true and reliable. The lens of the international famous brand product is often engraved with the manufacturer's trademark, which can be found by careful observation on the edge of the lens.
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%.
What are the colors of the fishing polarizer?
Amber, yellow, or orange lenses are very suitable for wearing on cloudy days. They can have a very clear vision, but they are not suitable for use on sunny days. Gray or dark green lenses can maintain the most natural original color when viewing objects, which is a good choice. Sunglasses are not only required to be worn in summer but they must also be used throughout the year. Wear it on sunny days and also on cloudy days. Don't think that the sun is not strong on cloudy days and the weather is not hot, so you don't need to wear sunglasses. The harmful ultraviolet rays will harm your eyes unknowingly. Therefore, even if it is a cloudy day with thin clouds, you must still wear sunglasses to protect your eyes.
How to choose frames?
Of course, the best way is to try it on many times. The visual effect is more direct and reliable than trying on. Spend more time and you can find your own style suitable for you.
In addition, where comfort and aesthetics permit, choose the size as large as possible so that the view will be larger. However, there are some optometric parameters that limit the selection of frames. For example, if the pupil distance is very small, choose a size that is too large is not suitable. Try not to choose the product with spray paint on the surface, because durable time is shorter.
You should pay special attention to that TR, plastic steel, stainless steel, wood, β titanium glasses temple may not be adjusted. When trying on, it should be noted that the weight of the lens has not been added to the trying frame, to avoid the problem of discomfort (such as an easy slip of the frame) found after the preparation.
The cost of an eye exam
If you have a Walmart Vision Center near you and you need a new or updated prescription, you can schedule your eye exam there. Some vision centers have independent optometrists who work in offices next to Walmart. An eye exam at Walmart costs about $73, depending on where you live. Call your nearest Walmart Vision Center to get the exact price of an eye exam.
What is the best lens material?
The world's first resin lens was made of CR-39 material, and CR-39 is still the main optical lens material in Europe and the United States. After the end of World War II, people found that compared with glass, the main lens material at that time, the light transmittance of CR-39 is high, and it can block ultraviolet light. In addition, CR-39 can be dyed, not easy to fog, and has small dispersion (CR-39's Abbe number is 58) and other benefits.