New Logitech Dark Field Mice Operate On Glass

Slatterz writes "Logitech has introduced new mice that use two lasers rather than one to work on a variety of previously unusable surfaces. The first laser picks out imperfections in the surface of a tabletop while the second laser focuses on microscopic imperfections highlighted and uses those to direct the cursor. The technique, dubbed dark field microscopy, allows mice to be used on almost any surface, including glass (as long as it is more than 4mm thick)."