Design principle of progressive multifocal lens
For the same piece of the lens, the top is used to see far, the bottom is used to see close. The upper and lower degrees are different.
There is not a sudden change in the distance degree fixed above the lens to the near degree fixed below the lens, but a gradual transition between the two through gradual changes in refractive power, which has special benefits over common bifocals or trifocal lenses.
The Benefits of Anti-Glare Glasses
As is well known, glare is the excessive brightness caused by direct light or reflected light. It often occurs when sunlight bounces off a reflective surface like water or snow. Of course, anti-glare glasses can also be caused by other factors.
Standard plastic lenses are able to reflect approximately 8% of the light that reaches your glasses and high-index lenses often reflect up to 12% of available light. Hence, anti-glare glasses come in a lot of advantages.
The anti-reflective glasses can reduce eye strain and make your eyeglasses look more attractive because the anti-reflective coating can eliminate reflections from the front and back surfaces of your eyeglass lenses. With this feature, more light can pass through your lenses to improve your vision with fewer distractions and the lenses look nearly invisible.
In addition, anti-glare glasses are helpful to high-index lenses, which reflect more light than regular plastic lenses. In general, the higher the index of refraction of the lens material, the more light will be reflected from the surface of the lenses.
Anti-glare glasses can protect your eyes from UV rays (sunlight that doesn’t appear on our visual spectrum). This feature can be enhanced by some photochromatic or polarized lenses.
How to clean the lenses?
When wiping lenses (especially the rimless glasses of resin lens), you must use a special wipe lens or soft handkerchief or paper. When you wipe the lens, you can only wipe it in one direction, not in circles, and don't touch the lens with your fingers. When the lens is stained with dust and sand, it should be washed with water before wiping, otherwise, the lens is likely to be abraded, and the operation should be gentle. At ordinary times, when cleaning, do not exert too much force, pay attention to the grasp of strength. When wiping the lens, it is best to take the side frame with one hand, and the other hand takes the glasses cloth to wipe gently. In order to prevent the lens film layer falls off, do not use alkaline detergent to wipe the lens. Therefore, when bathing or playing at the seaside, glasses should be properly kept to avoid water vapor or seawater caused by corrosion of glasses.
How do you buy prescription glasses on GlassesUSA?
Fill out a form on their website to enter a prescription, choose to have them follow up and require it later, or use their prescription scanner app on an existing pair of glasses. However, the app isn't always easy to use. You'll need your phone, a computer with enabled cookies, your glasses, and a magnetic stripe card to determine the size.
Wide-rimmed Clear sunglasses
Wide-rimmed Clear glasses cover almost the most area of your cheeks, even covering almost half of your cheeks.
Conservatoire Light gray clear frame sunglasses
Conservatoire International De Lunettes, founded in 2013 in Italy, specializes in fashion and retro glasses and sunglasses. Starting from the classic glasses of the past, new research results, photography, film, and retro elements are integrated into the design of glasses. These shapes may have been used by a classic character, or they may have been historical design elements, modernizing them to create a sense of fashion.
Cellulose Acetate
Acetate is a kind of thermoplastic resin obtained by esterifying acetic acid to acetic anhydride under the action of a catalyst. Acetate is resistant to water, gasoline, mineral oil, and lipids, weak alkaline solutions, and acids, excellent weather resistance, not resistant to ethanol, strong acids, and strong alkaline solutions. During thermoforming, it is very necessary to dry the material before forming. Acetate was born in the early 20th century, and was successfully trial-produced and industrialized by the UK in the early 1920s. At present, it is the second-largest variety in cellulose fiber after viscose fiber. Acetate can be used to make textiles, cigarette filters, film bases, and plastic products.
Superior properties of titanium alloy
The specific strength (strength/density) of titanium alloy is far higher than other metal structural materials, which can produce high unit strength, good rigidity parts.The engine parts, frames, fasteners, and landing gear are all made of titanium.It can still maintain the demanded strength at medium temperature and can work for a long time at 450 ~ 500℃.
