Well, augmented reality glasses are on the cutting edge, but there is another high-tech advance coming glasses that allow you to see the oxygen levels in people's blood. Interesting, yes. Party trick, hopefully. Invasion of privacy, kind of...?
The glasses enhance some of the colors that we can see, making the contrast between different blood concentrations more prominent. This allows, for example, doctors to see trauma through the skin. Or security officers to see how nervous you are. Or a date to see when you are lying.
It's not really a privacy issue. You can't hide something like that, because it is in plain sight all the time, anyway. It just makes you wonder if you can train yourself to see, for example, O2 levels in blood through skin without these glasses. Being able to do that could make you into a super hero!