It reads glass!
We like optical mice and wouldn't dream of going back to the old, mechanical ball and roller ways – unless if we're trying to use our mice on a surface that's difficult to track on. Those of us with fancy glass desks know that getting an optical mouse to work on glass is a futile effort without the addition of a mousepad. Thanks to Logitech's new "Darkfield" technology, tracking on glass is now possible.
Logitech today announced two new premium mice, the Anywhere Mouse MX and the Performance Mouse MX, that will track on clear glass at least 4 mm thick as well as lacquered desks.
Perhaps just as good news is that these new mice also work with Logitech's unified USB nano receiver.