My 13-year old son explained to me the other day that it is impossible to be invisible. Apparently, to be seen, protons (or is it photons, no wait that’s Star Trek) bounce off you.
Now, for your eyes to see they must be “hit” by these protons. So if your eyes can see something they must be visible because when your eyes get “hit” by protons to see they become visible to someone else’s eyes.
I almost explained to him that I learned this from comics over 30 years ago. I think it was Archie’s cousin Sabrina. When she was invisible you could still see the outline of her eyes.
I bit my tongue.