I can voluntarily imitate nystagmus, too. I think that sounds like a really creepy ice breaker, but then I don't like strangers in general.I can vibrate my eyes. I don’t really know what it’s called but I have been doing it since I was 5. I only use it as an ice breaker with people, I usually show it to someone and they get really interested.
But I’ve never seen myself doing it so I don’t know what it looks like.