Types and Features Of Photochromic Lenses
Some glasses assist you to defend your sights from the harmful effects of UV-rays, but they are not suitable for those who wear regular corrective glasses or want spectacle lenses to react to the light level, because it changes during the day. For such people, special photochromic spectacle lenses have been created, or, as they are also called, chameleons.
They got their name due to the amazing feature of becoming darker or lighter, depending on the illumination. Usually, a photochromic coating is transparent and does not differ from classic ones, when the sun is dim, they are slightly darkened, and when the sun is bright, they darken a lot and protect the eyes no worse than ordinary glasses.
What Are The Photochromic Lenses
The secret is in the particles of photochromic elements. Under the influence of ultraviolet light, they change their structure, while they stop transmitting light.
As a result, such glasses are dimmed. As soon as the UV radiation disappears, the structure of the substances changes again.
Today there are several technologies for the production of changeable vivid transmission lenses.
- Photochromic coating. A thin layer of such particles is applied to the lens surface to darken it. This method is currently considered outdated, since the degree of light absorption is not high enough, and the time for darkening and lightening is long.
- The introduction of photochromic agents into the material. Ready lenses are impregnated with them. The common well-known brand is the Transitions group.
- Volumetric distributed technology. The bottom line is that photochromic molecules are evenly located in the lens material during its manufacture. These ocular products are manufactured by SunSensors.
The main advantage of this coating of glasses is that it can be applied to prescription lenses.