Photochromic Lenses become darker by reacting to certain levels of UltraViolet Light which are common to sunlight. This means that while indoors the lenses are essentially clear, but when in strong sunlight a tint will appear on the Lenses.
Photochromic Lenses fall into two catagories:
Although these two types of Lens serve the same function, they each have unique benfeits, so follow the links above to find out which is best for you.
Did you know:-
Photochromic Lenses are often not suitable for driving in strong light, because a windscreen can reduce the amount of Ulraviolet light and the lens cannot become as dark as necessary.
Photochromic Lenses can take a few minutes to react properly, this is especially true in countries like the UK, where sunlight, although bright, has a lower UltraViolet content.
Photochromic Lenses react quicker with age and revert to there clear state more slowly than when they are new.