Photo chromatic lenses are a popular solution for people who wear prescription glasses regularly and want to protect their eyes from UV Rays and reduce exposure to harsh sunlight. Photo chromatic glasses reduce the hassle of carrying separate glasses indoors and outdoors. With a photo chromic lens glass, it's easy to go from outdoors to indoors and vice versa without a problem.
The photo chromatic lens usually has an invisible or lightly tinted layer that darkens when exposed to certain amounts and certain types of lights. For example, a photo chromic lens will change to a dark or light brown tint upon direct exposure to sunlight. The glasses are great for people who constantly shift between indoors and outdoors and have prescription glasses for their vision correction. Photo chromic lenses automatically change the glass tint from nearly invisible to darken depending on the amount and type of sunlight and the type of sunlight.
Photo chromic lenses are available in most lens materials and designs. These include high-index lenses, bifocals and progressive ones that can be made into tinted lenses. An added benefit of these lenses is that your eyes are 100 percent shielded of the sun's harmful UVA and UVB rays. These ultraviolet radiations are not good for the eyes and studies have shown that exposure to these rays can increase risks of having Cataracts and other health problems.
Though these lenses cost more than clear eyeglass lenses, they are convenient. They come with specially tinted lenses that reduce the need to carry a pair of prescription sunglasses all the time.
The molecules responsible for causing photo chromic lenses to darken get activated by the UV radiation from the sun. UV rays penetrate clouds, which ensure the glasses will darken on cloudy days as well as sunny days. But because the windshield and window glass of cars and trucks blocks most UV rays, they typically won't get as dark inside a vehicle as they do outdoors.
You can get Photo chromic lenses done in nearly all types of eyeglasses. Depending on the brand there can be a subtle yellow tint. To get the best lenses with minimal spending one must keep track of these things:
Branded: You should decide your budget and choose a reputable brand. Most optical stores and online portals allow adding photo chromic lenses to their glasses so check out the brands and choose a reputable one for the lenses.
Protection: These special lenses allow sun protection as well as soothe the eyes with a tinted lens that blocks out harsh sun rays. This makes it a great choice to wear all day. With these lenses your spectacles will become your sunglasses in harsh daylight.