Display/Graphics Problems

Hi,
The display on the Mac computer at my work has been changed so that all the icons are very tiny, the fonts are very large, and when I move the mouse, the entire screen moves so that most of the time a part of the screen is hidden and I have to jiggle the mouse around to read everything - I'm not scrolling, it just automatically does it without me clicking. I am not really familiar with Macs but I do know how to get to system preferences, and I can't think what option might make the screen do that. It really makes the computer harder to use - does anyone know what it is? I also didn't see where I could make the icons bigger or smaller ,it doesn't seem like the Desktop/Display really does it . Thanks in advance!!