There is a wide range of photocromic lenses on the market, that is, clear lenses which react with UV and produce a tint dependent on the amount of UV present.
When wearing photochromic lenses even a dull day some reaction will occur producing a very pale tint and then on a very bright day where more UV is present they will turn quite dark. When wearing them indoors they will become clear.
The idea behind photochromic lenses is that they will provide the correct amount of protection for the varying light conditions you experience, offering you optimum protection, and meaning you only need one pair of glasses.
The two most common photocromic lenses are:
Transitions is a brand name for what are the fastest reacting lens on the market – taking just 30 seconds to react into sunglasses. They take slightly longer to go clear again once inside.
Reactolite is a brand name given to a glass photochromic lens. They do not react as well as the polycarbonate Transitions and are much heavier to wear. However, one advantage they have is that the glass reactolite tends to work much better behind a car windscreen.
In most cases, we find patients prefer the Transitions lens because of the overall comfort and performance, but we’re happy for patients to see both and see which they like best.