The mystery of photochromic glasses

In outdoor activities, everything in the day will be bathed in the sun, which for a long time in the outdoor friends, not only because of harsh and feel uncomfortable, more hinder the appreciation of beautiful natural scenery, even affect the safety. So, many people wear “color changing” glasses to protect their eyes from bright light. A suitable color-changing glasses can not only help you protect your eyes from the harsh sun, protect your eyes from ultraviolet rays (reduce the incidence of cataracts), but also be easy to use, especially suitable for short-sighted friends! So do you know how color-changing glasses “change color”?
Color-changing glasses are glasses whose lenses automatically change color in response to changes in ambient light. Color-changing glasses can protect the wearer’s eyes by changing the color of the lens when exposed to strong light, while the lens quickly returns to a colorless and transparent state when there is no strong light. Color-changing glasses are widely used in outdoor activity places with strong sunlight, snow and indoor workplaces with strong light sources, which can effectively prevent the damage to eyes caused by strong light exposure.
The earliest color-changing glasses were made using photochromic technology. In 1960s, American scientists Amistead and Stooky first discovered the retrochromic performance of glass containing silver halide. Then, based on this, American Corning Company developed color-changing glasses by mixing silver halide and photosensitizer into glass as lenses. However, the changing speed of glasses made with silver halide glass is slow, and there are some disadvantages such as high cost and difficulty in processing. At the same time, with the wide application of resin materials in the field of spectacles and the emergence of new photochromic materials, the color-changing glasses using silver halide glass as color-changing lenses have gradually withdrawn from the mainstream market. Instead, color-changing glasses are made by adding new photochromic materials on the resin lenses. The key to this technique is to find suitable photochromic materials. Our company has a wide variety of photochromic dyes OP powder and photochromic microcapsules MC powder, among which, OP powder itself does not change color in light, need a certain medium (solvent, resin, plastic, etc.) to sensitize and change color, dissolved in solvents of different polarity, the color change will be different. The product is colorless (or the natural color of the product) under the indoor light source, in the ultraviolet light source and sunlight (including ultraviolet light) irradiation quickly show the product color, isolation UV light source products become colorless (or the natural color of the product). OP powder has a variety of colors to choose, can be mixed with different OP powder, with more color changes. Photochromic microcapsule MC powder is a kind of photochromic powder material made by special processing OP powder coated in microcapsules. It changes color quickly under ultraviolet light source and sunlight (including ultraviolet light), and can be directly added to the corresponding products in proportion. It has the characteristics of bright color, high temperature resistance, solvent resistance and high fatigue resistance. It is promising to use photochromic materials in resin lenses.
In the face of different colors of discolored glasses, how should we choose? Mainly from the functional characteristics of the lens, the use of glasses, personal color requirements to consider. Photochromic lenses can also be made in a variety of colors, such as gray, tan, etc.
1. Grey lenses
It can absorb infrared ray and 98% ultraviolet ray. The biggest advantage of the gray lens is that it will not change the original color of the scene because of the lens, and the biggest satisfaction is that it can reduce the intensity of light very effectively. The gray lens can absorb any color spectrum evenly, so the scenery will only be darkened, but there will be no obvious color difference, showing the true natural feeling. Belongs to the neutral color system, in line with all people use.
2. Pink lenses
This is a very common color. It absorbs 95 percent of ultraviolet light. If it is as the correction of vision glasses, must often wear the lady had better choose the light red lens, because the light red lens absorption function is better, and can make the overall light intensity is reduced, so the wearer will feel more comfortable.
3. Light purple lenses
Like pink lenses, they are more popular with mature women because of their relatively dark color.
4. Tan lenses
Absorbing up to 100% of UV rays, the tawny lenses are popular with wearers because they filter out large amounts of blue light and improve visual contrast and clarity. Especially in the case of serious air pollution or fog wearing effect is better. Generally, it can block the reflected light on the smooth and bright surface, and the wearer can still see fine parts. It is an ideal choice for drivers. For middle-aged and elderly patients with high vision above 600 degrees, it can be given priority.
5. Light blue lenses
Sun blue lenses can be worn on the beach, which can effectively filter out the light blue reflected by the sea and the sky. Blue lenses should be avoided when driving because they can confuse us with the colors of traffic signals. Outlook: Color-changing glasses not only darken and brighten with the intensity of light, but also absorb ultraviolet rays, which are harmful to human eyes. If you replace all the Windows with photochromic glass, the sun won’t shine into the room on sunny days; Cloudy days or morning, dusk, outdoor light is not blocked, indoor is still bright. It’s like having self-shading curtains on the Windows. In some high – class hotels, restaurants, has installed color-changing glass. The cab of the car and the tour bus loaded with this kind of photochromic glass, in direct sunlight, even do not have to wear color glasses, the carriage has been keeping the soft light, to avoid the glare of the sun and exposure, so that everyone how happy ah!