A very weird thing happened today - my left eye got blurry right in the center and then, over the next hour, the blurry spot became an ever widening ring of blur (the center cleared up and the blurry area was a small ring at first). The ring slowly got wider and wider and eventually disappeared and I'm seeing fine now. I've never had any problems before and this frightens me.
Have you ever heard of this and what could it be?