To the OP:
It's a dysfunction of the lacrimals, caused by a small, not-severe-at-all infection. I've had it twice in my life, once when I was a kid and a lot other kids had it at the same time - apparently it was something in the water of the pool we attended in the lil summer town. You got the "it goes out" version. The "it stays in" version is less painful and annoying, but absolutely icky to watch.