My Mother just had this occur to her yesterday... have you found any information on the cause?
7/3/2016 I have something that sounds just like that! However, mine keeps rolling, vertically, for about 15 minutes at which point it develops into full blown double vision. It all starts with a blurring of my vision. The whole episode lasts about 2 hours to get back to 95% ok.
I've had 7 episodes now, first one on its own, then a week later 4 days in a row, then another week later 2 days in a row.
Can't find anything on the Internet... Was hopeful with nystagmus but it turns out that's not it. Any comments appreciated.
I have never heard of anything exactly like that, either, but there is an eye problem called nystagmus in which the eyes involuntarily jerk around. It has a number of causes, some benign and some not very good at all. Sometimes it is associated with a sense of vertigo, also.
The wikipedia article on nystagmus has a small video illustrating it, and I think there are some on youtube as well.
See if you can find a friend who will observe you when you have one of these episodes and tell you if your eyes are actually moving.
If they are, you are going to have to make an appointment with a doctor to evaluate you, no way around it.