Sunglasses are really popular nowadays, especially for this hot summer, and they are effective to block the harmful UV rays coming from the sunlight, so, they are becoming a necessary accessory for people to go outside from indoors, just as their cats or purses! And as the development of today’s advanced optical tech, individuals who have the eye disease including myopia and hyperopia can also have alternative choice of wearing prescription sunglasses, at this situation, you don’t need to carry a special clip-on in your pocket, and switch it when you are from indoors to outdoors or turn back! However, when people come from outside, their vision will be darken as the sunglasses lenses eliminated much visible light, and it may be considered to be a wired behavior to wear sunglasses for working, even they are just prescription sunglasses. So, is there a kind of prescription eyeglasses that can turn to sunglasses automatically when people go outside, while still the same when they are inside?
Absolutely there is, and we call them photochromic lenses, which have the same effect of ultra-violet rays blocking just as sunglasses, but can change their color according to the intensity of UV rays they are exposed to, and such lenses become almost opaque. When you are coming from outside, the lenses come back to their original color and darkness disappears. The reason why can photochromic lenses change color is because of the silver halides, which are embed into lenses gradually, when they are exposed to the light, the crystals can absorb it, the stronger the light is, the darker your lenses will be! On the other side, if the UV radiation is no longer exist, the eyeglasses lenses will become clear! What’s more, today, we also hear about transition eyeglasses, actually, they are one of the most popular photochromic eyeglasses lenses, not like traditional lenses, which distributing silver halides particles throughout a lens, they use a thin layer or coating that also has the effect of color changing in transition lenses, and this method have a more effective conclusion of changing color!
Today, there are many people want to add their Rx in such a lens, and we call them photochromic prescription eyeglasses. When refer to buy such eye wears, it is always a good idea to choose online sites, not only because of time-saving, but also dollars-saving! Take prescription glasses online for example, it provides customers nearly a half price discount!