Testing of aspheric lens
The optical axis of the optical center just overlaps with the visual axis of the eye, which is the most ideal state. Because the light from the edge cannot form a focus on the optical axis, when the optical axis does not overlap with the visual axis (the difference is greater than 2mm), such unclear and scattered imaging results will occur. When choosing frames and aspheric lenses, you need to ensure that they fit correctly, to achieve the best visual and decorative effects. Simply put, due to the special design of the lens, we found through a calculation that the optical center should move down 1mm higher than the pupil for every 2° increase in front inclination angle. Otherwise, the wrong pupil height will cause the lens to look like astigmatism, and cause discomfort. For glasses with aspheric lenses, there must be an inclination angle after wearing. The specific angle varies from person to person.
Injection frame
Acetate cellulose pellets are extruded by an injection molding machine, which is called an injection frame. Its characteristic is that it saves raw materials, can be mass-produced, has a lower cost, and is cheaper than a plate rack. But the firmness is not as good as the plate frame. However, injection frames are mostly used for glasses for the elderly and children because of their lightweight and resistance to allergies. The injection frame is made of laminated plastic. It is made by pasting a thin layer of plastic of one color on another thicker layer of plastic. Thick materials are mostly transparent pigments. It is also made of three or more layers of plastic.
How to protect rimless glasses?
With the continuous improvement of people's living standards, many people begin to pay attention to their quality of life. In the past, many people thought that wearing glasses was for correcting eyesight glasses, but now more and more people use them for decoration, and rimless glasses meet the needs of consumers. Because of its light structure, giving people a sense of fashion, so it is loved by many business people. So how do you protect your rimless glasses?
Discoloration time and fading time for color-changing lenses
In general, color-changing lenses take about 30 seconds to 1 minute to darken on average when exposed to sunlight/UV and will continue to darken for about 10 minutes to reach the lens depth of full-color sunglasses. Color-changing lenses of good quality and workmanship are restored to an almost clear and transparent state in 2 minutes and completely cleared in 5 minutes, although the high temperature can affect this. If you want to change a single color change lens, the color of the old and new lenses will be inconsistent. This is because the discoloration performance of the old lens will be reduced due to the long-term use of the discoloration agent. Therefore, in order to ensure the normal use and aesthetic appearance, it is usually recommended to replace the two lenses at the same time.
Magnesium aluminum spectacle frame
One of the characteristics of magnesium-aluminum spectacle frames is that they are resistant to corrosion, sweat and wear. In addition, spectacle frames made of magnesium-aluminum are also rich in color and look very textured, so many business people like to use such spectacle frames to display Its own charm.
How do I know what size glasses frame I need?
With unified factory product size, why others can wear without problems, but there is a problem when I wear the glasses? There are differences between the contours of each person's face, including factors such as the width of the head, the distance between the ears and the corners of the eyes as the crow flies, the thickness of the bridge of the nose, and so on, which involves ergonomics. But there is one thing we can agree on. When people with the same ear distance wear the same type of glasses, they have different feelings, even if the arm length of the glasses is the same. People with fatter faces will feel uncomfortable. The face will be uncomfortable because the ear distance is the same, but the face width is not the same, resulting in an increased oblique distance of the temple, resulting in a sense of pressure.
It is very simple to solve this problem. You need to look at a variety of parameters in the frame of the glasses, including the total width of the frame, the length of the arm. These parameters will be reflected in a qualified spectacle frame.
Is it a good idea to buy glasses online?
If the product is purchased from a reputable and trusted retailer, buying glasses online is just as safe as buying any other product online. Buying custom-made products, such as 'prescription glasses' online, is a bit more complicated than buying regular 'ready-made' glasses. All uploaded prescription glasses orders are reviewed and notified when serious errors are found in the prescription. All prescription glasses to be shipped are also carefully checked by quality control personnel to ensure that the glasses match the required prescription to the highest standard.
