It sounds like that mouse got into your scotch, Dan.
Well, sometimes, a sighted person can help. My wife looked at the screen and saw immediately that the mouse pointer was being pressed continually, it was going totally bonkers. Apparently, I had set the mouse back beside the computer in a place that aused the scroll wheel to be turned or halfway between clicks or something. Moving the mouse brought everything back into focus and interestingly, there was no audible indication that such a thing was happening. So, it was a mouse in the works, bad mouse, no cheese.