The lenses of prescription glasses
Common materials for lenses include glass, resin, and PC. The glass is fragile and heavy, and few people wear it anymore. PC film is tough and not fragile, but it is not resistant to high temperature and the surface is easily scratched. The most common type of lens on the market today is the resin lens, which is light in weight, hard to break, and reasonable in price. At present, it is generally recommended that you choose resin sheets, and it is recommended that people with ultra-high myopia choose glass sheets.
Generally, lenses can be divided into spherical and aspherical surfaces according to different curvature designs. When choosing, refer to the degree of the eye. For people with lower degrees, There are fewer differences between the two shapes. For people with moderate to high myopia, aspherical lenses will have better imaging effects and clearer vision.
When choosing a lens, a parameter that is often mentioned is the refractive index. Common refractive indexes are 1.56, 1.60, 1.67, and 1.74. With the same degree, the higher the refractive index, the thinner the lens.
How to Get Used to Progressive Lenses?
It is common that your vision may change when you are over age 40. You can find it is happening when have to hold your favorite book, the daily newspaper, or a restaurant menu farther away just to read it. This is an eye condition called presbyopia. It is normal and almost all of us get it as we reach middle age.
This eye condition often can be corrected by progressive lenses which allow you to see objects from far to near clearly. With progressive lenses, you do not have to switch your glasses to see far or near objects frequently.
However, since progressive glasses have three different prescriptions in one lens, it may be difficult for some people to adapt to the new ones. So, in this post, we will show you how to get used to progressive lenses.
Armada Optical Services
Armada Optical Services is a full-service laboratory dedicated to providing one of the best safe prescription eyewear programs for your organization. They now have different kinds of safety frames, including plastic, stainless steel, frameless, and titanium. Armada provides all the safety lenses available on the market today, including special lenses for welding, furnaces, etc. The company has certified polycarbonate and Trivex (Trilogy) lenses to meet the new ANSI Z87.1-2003 standard. They provide a variety of high impact lenses. Armada is the laboratory for safety, quality, price, selection, service, and knowledge.
How to see if the lenses are too high?
- Look at an object in a distance 65 feet away or more.
- If you can’t see it clear, keep your eyes on the object and lower your chin. Check whether you can see clearly while looking through a more upper part in the lens than your lenses are too high.
Then you need to watch the difference in the blurriness on the contours of the roadsign.
Now, we will show you how to check if your lenses are too low. Hold something you want to read in your hands and lower your look with your eyes. Do not move your chin down as you look down. If you can’t read without lifting the glasses, the lenses are too low.
Glasses donation is also a form of recycling.
The old glasses were donated, and the love glasses were favored and recognized by the public. It is mainly aimed at orphans, left-behind children, single-parent families, and adolescents with mental retardation in poor mountainous areas. It lets the children who can not afford glasses really feel the care and warmth brought by people from all walks of life. Encourage them to take good care of their eyesight, study happily and grow healthily. And it can enhance the self-health care consciousness of young students.
Warby Parker
Warby Parker started the Home optics industry with Home Try On, but the well-known startup's frames are becoming more common. Select 5 frames to test for 5 days and they will be mailed to you free of charge. Try it for five days and see which one you like. You can buy it yourself online. They'll send you a new one.
What is the best lens material?
Early lenses were made of natural materials because they were easy to get. But natural materials have obvious drawbacks. According to records of the Qing Dynasty, Emperor Yongzheng wore crystal glasses given by the imperial court, which greatly improved the efficiency of reading documents. However, because of the cold nature, the crystal will make the temperature around the eyes low when wearing, and part of the crystal lens has color so that the light into the eyes becomes soft.
