Cdr Chris Hadfield: So here's a common question. Can you cry in space? Do tears work? Well, let's try it out. I can't cry on command, but I'm going to take some water, drinking water, put it in my eye just as if I was crying, and let's see what happens. So nice and stable for you here. Here we go.
So just as if I started crying, my eye is full of tears. But you can see it just forms a ball on my eye. In fact, I could put more water in. And so if you keep crying, you just end up with a bigger and bigger ball of water in your eye, until eventually it crosses across your nose and gets into your other eye, or evaporates, or maybe spreads over your cheek, or you grab a towel and dry it up.
So yes, I've gotten things in my eye. Your eyes will definitely cry in space. But the big difference is tears don't fall. So grab a hanky.