In case you don't know it, the Navy is not the 1970s "Village People" branch of the military.  These guys do some cool stuff and are making even cooler toys to do it with.

Want to find future tech for megawatt-class laser beams in next-generation weapon systems?  The Navy.   Want to go completely science fiction and find work on a railgun with a projectile that rides an electromagnetic current to its target?  The Navy.

Now they are redoing sunglasses.   Later this year, Special Warfare Command (those are SEALs to you and me) will get Fast-Tint Protective Eyewear (FTPE), which are LCD ballistic eyewear that change color much faster than the kind of transitional lenses we civilians might get - 0.5 seconds to adapt to new lighting conditions. 

Fast-Tint Protective Eyewear FTPE
Fast-Tint Protective Eyewear (FTPE).  Photo: ONR

The Navy wants commandos to be able to keep their glasses on when moving from outside to inside environments and not have to change lenses and tasked the Office of Naval Research with finding a solution.   Not waiting for lenses to adjust or, worse, taking off protective eyewear, preserves 'operational tempo' though, if you are like me, you thought there was only one tempo - shock, kill, go home.

How does it work?  Their liquid crystal solution in each layer of the lenses has customized dyes that change the tint when an electric charge is applied, in the automated mode, or manually when a button is pushed on the frame.   Tints are amber, blue, dark gray or clear.   The lenses are designed to meet the American National Standards Institute's ballistic impact safety requirements.

Jeremy Kaplan at Fox News notes that the folks behind the technology, AlphaMicro of Ohio, have been developing this for over a dozen years and debuted the Uvex F1 Magic Goggles for skiers a while back, though curved LCD screens thin enough to be sunglasses are obviously a much bigger technological (and therefore physics) leap.

When will these arrive in stores for us non-commandos?  Hard to say, but it won't be long once the handmade prototypes are shown to be military class.