Oh yeah....night vision goggles used a wee bit of the isotope too.
Sometime in the 1970s is when we were first given the goggles to play with.
They looked so ridiculous it was impossible for us not to laugh at each other.
They had a pair of 3 inch long by maybe 1/2 inch diameter tubes that stuck out of the main frame that gave the user a "Space Alien" look about himself...