Review: Logitech Performance Mouse MX

Glass: The final frontier. For as long as there have been optical mice, there have been disclaimers that they don't work on glass-topped desks or tables because the smooth, featureless surface doesn't give the mouse sensor enough contrast to compare its position from one millisecond to the next. Even as LED optical designs have yielded to fancier laser mice that can "see" more sharply and detect finer changes in terrain, you've had to slip a mouse pad or magazine or piece of paper between mouse and desk if the latter's made of glass.

According to Logitech, that just won't do in a world where 40 percent of users surveyed had a glass-topped table or desk at home. The company's two newest mice break the glass barrier, so to speak, with technology given the über-cool name of Darkfield Laser Tracking. The full-sized Performance Mouse MX ($100) and portable Anywhere Mouse MX ($80) combine dual lasers with an indirect lighting scheme inspired by dark field microscopy that throws even the most minute scratches and dust particles into relief, so a glass surface (minimum 4mm thick) or shiny lacquered desk will work as well as wood, tile, a pants leg, an airline tray table, or what have you.