From time to time I have a recurring dream where I am either driving, or doing something else, and suddenly my vision gets blurry and it feels like my eyes are about to close, as if I'm falling asleep.

A couple times I had this happen in a dream while I'm driving. And I'm fighting to stay awake, but my vision goes black. Usually I wake myself up as everything goes black. Does anyone have any ideas what this may mean, or is it stress related?