I had that not that long ago. Dont know what it is. i'll post a EDIT if i find out.
--Edit--
k, I found some research.
Yep I agree with Izzy. That is exactly what you are describing. We call it an ophthalmic migraine because it occurs within the eyes and does not necessarily cause a headache. It usually starts with a zigzag or kaleidoscope of lights in the peripheral vision and works its way to the center vision and then back out again, causing difficulty seeing in the area affected. You may or may not get a full blown headache or a mild headache with it. You may also feel nauseated, and tired afterwards.
There are certain cheeses, processed meats and certain types of peanuts that can attribute to these as well as chocolate. If it continues to be a problem, seek medical advice. I will give you a little heads up. You can make an appt. with an ophthalmologist, but most will tell you there is nothing they can do for it.
GO TO THE doctors aswell. Just incase its serious =X.