No, I use a mouse.

As I am typing this, the screen/font reduced several sizes. And per my post above, it has happened when I am not even near the screen, when the computer is not being used, just has the display on.

This a.m. I have noticed that it also does such things as making other changes, scrolling up or down without my touching the controls. A browser also switches to a blank screen without my input. On these I can't be certain that I haven't touched the wrong controls, although just now as I kayboard in this reply, it seems to scroll without my touching anything except the keys.

At first I thought the problem was simply becoming acclimated to Windows 8.

I can see that some of the events might be from an unfamiliar keyboard--but the screen scrolled just now when I was not touching ANY keys, when my hands were off the keyboard. And then again and again. To the point that I am having difficulty finishing this.

Weird.