For those who wear glasses, protecting your eyes from the sun can become a real problem. Especially when you are in environments they foresee different intensities of light, choosing to wear sunglasses or transparent lenses can cause difficulties.
Fortunately, solutions have been developed for many years that allow for lenses that darken automatically, also said photochromic. Thanks to special precautions they become sensitive to light and change shades based on the amount of UVA, UVB and infrared rays received.
How do photochromic lenses work?
Thanks to a special treatment, the photochromic lenses they are coated with materials that through a chemical reaction they darken or become transparent again based on exposure to sunlight.
The reaction occurs in contact with i UVA, UVB and infrared rays. Although it seems a recent discovery, the first experiments were done as far back as the 1960s!
As the technology has refined, improving the aesthetic result, the comfort and the rapidity of the transition.
Mostly the transition speed in the transition from transparent to colored it was increased, coming to have a complete transition from dark to transparent (and vice versa) in just a few minutes.
The photochromic lenses do they darken in artificially lit environments?
If in the past it could happen that the glasses darkened even inside environments illuminated by artificial light, today the lenses change color only when illuminated by the UV rays of the sun.
Wear photochromic lenses it doesn't bother you inside your home or office, the glasses remain transparent and you do not notice any difference compared to glasses with standard lenses.
In addition, the modern photochromic lenses like those created by Essilor they also combine one darkening protection from blue rays, essential to avoid fatigue due to the excessive use of electronic devices.
Do they fully protect against UVA and UVB rays?
As with sunglasses, photochromic lenses have total protection from UV rays.
However, there are some specific situations in which it is advisable to use sunglasses instead of photochromic ones: when outdoor sports are practiced and in situations of bright light for example al big o in mountain.
In fact, doing outdoor sports and staying in places where the brightness and reflected light are very strong (for example sailing in the sea or cycling on the road) it is advisable to wear polarized glasses that have a total degree of coverage from UVA rays. and UVB.