It will be used in medicine,nurses will easily locate your best veins to take blood and so on. 
Good thing!
http://www.digitaltrends.com/mobile/think-google-glass-cool-x-ray-specs-can-see-skin/
Good thing!http://www.digitaltrends.com/mobile/think-google-glass-cool-x-ray-specs-can-see-skin/
The best product to be released in recent years the amount of times I've been stabbed by a nurse just for them to miss one of the veins is incrediable.