Very nice, but where's my Slow Glass?

Yes, this is interesting stuff: Electrochromatic Glass: Instant Darkening - Gizmodo

But for real imagination, try and find a copy of "Light of Other Days"
by Bob Shaw, a short story published in the 1960's. It's haunting - and has stayed with me in the many hears since I read it.

And apparently, it may be possible.

science, science fiction, light