The Georgia Tech glasses, currently under development, are clear eyeglasses that can manually take on a sunglass-style tint when the user wants them to.
The lenses are fitted with electrochromic polymers which respond to electrical current instead of ultraviolet light as is the case with traditional transitional lenses. The prototype glasses have a brown tint that can block up to 70% of incoming light in a matter of seconds.
As someone who briefly owned traditional transitional lenses, I think this is a great idea. Normal transitional lenses can take too long to transition and this can be a problem if you walk from the sunny outdoors into a dimly lit place and find yourself unable to see anything. The Georgia Tech glasses will certainly help get rid of that problem.