I Have Experienced Light Headness & Everything Becomes Blurred ...

I have experienced light headness & everything becomes blurred ... only a few seconds, but I have to hold onto something for fear of falling ... which occurred while I was on the treadmill at the gym. It doesn't happen often, however, I'm concerned it may happen while driving. Have read much on the net about 'inner-ear balance' ... which also has been prevalent for years ... my balance that is. Many other symptoms.