New Material For Fast-Change Sunglasses, Data Storage 133
sciencehabit writes "'Researchers have developed a material that almost instantaneously (30 ms) changes from clear to dark blue when exposed to ultraviolet light, and it just as quickly reverts to clear when the light is turned off. The new material, one of a class called photochromics, could be useful in optical data storage as well as in super-fancy sunglasses.'" A comment to the article notes some of the potential dangers of quick-change sunglasses.
epileptics-need-not-apply. Why not? (Score:5, Interesting)
Re:flicker probably not an issue (Score:5, Interesting)
as you might or might not know, the windshield filters the uv rays. phototropic glasses cannot function in a car.
But is the reverse reaction temperature sensitive? (Score:3, Interesting)
In hot conditions the temperature sensitive dark=>light process is favoured over the uv sensitive light=>dark process and they stay clear. I don't want glasses that change colour quickly, I want glasses that change stay dark on the beach.
The only use I have for my current "light sensitive" glasses is if I ever go to the Arctic in summer.
What's new? (Score:5, Interesting)
Re:The eye adapts slowly (Score:3, Interesting)
"Glass (like, for example, your windscreen) blocks UV. So, they don't actually work when you're driving."
Except in my experience that's not really true.
I had this discussion with my optician last time I got a new pair of driving glasses, and they do darken while driving despite the fact that the windshield should block the UV (though, admittedly, not as dark as they used to go when I drove a convertible).
I can only guess that the windshield doesn't block the full range of frequencies that cause the glasses to darken.
Photosensitive Welding goggles work well (Score:3, Interesting)
I've taken a couple of welding courses over at Techshop [techshop.ws], and there's a range of welding goggle technology out there. Electric-arc welding (MIG, TIG, old-style stick, etc.) needs really dark goggles, and photo-sensitive welding goggles are available and really cool. They're adjustable-strength, and I think the technology is LCDs driven by a photocell, as opposed to a purely chemical mechanism like sunglasses. (For gas torch welding, the glasses don't need to be as strong, and the standard "adjustable" technology is just flip-up green lenses.) Unfortunately, the automatic ones cost about $200, as opposed to non-adjustable welding helmets that are usually under $100 or torch-welding goggles that are priced like sunglasses.
If this technology is dark enough for welding, ,and not too expensive it's fast enough to be effective.