Photochromic Lenses

"Photchromic lenses are sometimes referred to as transition lenses, reactalite lenses or sunsensor lenses.
Photochromic lenses darken on exposure to sunlight and protect the eyes from ultraviolet radiation. Excessive exposure can cause permanent damage to the cornea and conjunctiva. Good photochromic lenses block out 100% of the most harmful rays of the sun, 100% of the time, adapting to changes in light and darkening in seconds.

Whilst sunglasses give comfort in very bright conditions by reducing the total amount of light and glare reaching the eye, they are not always convenient in changing light conditions and care must be taken that they meet Standard BS 2724 otherwise they won’t protect the eye from the sun’s damaging ultraviolet rays. In fact, non-UV absorbing lenses can do more harm than not wearing any protection at all because, behind a dark tint, the pupil increases in size allowing the harmful rays through."