If you’re one of the many dual-display Mac users plagued by Apple’s annoying disappearing cursor, the easiest way to get your cursor back is to drag a window from the working display to the no-cursor display, (If the display that is working correctly doesn’t have a window open, right-click the desktop and choose ‘get info’ which will open a small info window.)

You don’t have to drop the window onto the other desktop, simply drag it over, then drag it back. For some reason dragging something restores the cursor.

IF THAT DOESN’T WORK: The problme also seems to go away if you sleep the displays (keyboard shortcut Control + Shift + Eject) then hit a key to wake them back up.