Photochromic lenses are one of the cleverest inventions we can think of in every day use – how cool is this? You go out in the sun – they go dark. You come indoors – they go clear again. All without flicking a switch or the wearer thinking about it at all. A remarkably clever concept that for millions of happy customers makes every day life that little bit easier. We’d like to answer some of the queries we come across about these intelligent lenses.
My old photochromic lenses look really dark compared to my new ones – do they make them in lighter shades?
The older the lenses, the darker they will stay. Over time and constant exposure to UV they stay darker, so a new pair will always look lighter.
Will they look dark indoors?
No – it’s the Ultra Violet in sunlight that makes them react, so only direct exposure to the sun will make them change. This is why some windscreens will inhibit the reaction, as they filter UV out.
I broke one lens and the optician says I have to replace both, why?
As the lenses are worn the colour will alter over time. The colour won’t match if you try to replace one lens.
I’m quite short sighted, the optician says my lenses will look dark round the edges. Why?!
If you’re short sighted your lenses are thicker round the edge than at the centre. The higher your prescription, the more exaggerated the effect. Photochromic lenses contain crystals which react on exposure to UV, rather like the film in a camera. The thicker the lens, the more dense the crystals, so thick areas will look darker.
Do they give UV protection if they react to UV?
Yes, check the brand you’re ordering if this is a concern to you, but all the brands we are aware of don’t let UV through to the eye.
What difference do the colours make?
The common colours nowadays are grey or brown. They go equally dark, brown is warmer to look through, but does alter colours slightly. Grey is cooler, but much more neutral.
Can you drive in them at night, do they count as tinted lenses?
Although they always have a pale residual tint, photochromics are practically clear n the absence of UV. Therefore they are perfectly safe to wear at night.