Remember when you had to buy a special cleaner to wipe your (mouse) ball down every time it got a little grimy? If you don't, thank you for making us feel super-old. If you do, then you also remember how crazy an optical mouse was. Optical mice work using either an LED or laser diode along with a image processor to track the surface it's sliding across. Developed in the '80s by two teams—one at MIT and one at Xerox—it wasn't until 1998 when Travis N. Blalock, Richard A. Baumgartner, Thomas Hornak, and Mark T. Smith at HP Labs patented the technology that it became a hit with the masses.