Tobii may not be a household brand name yet, but that doesn't make the company's eye-tracking technology any less impressive. At last year's CES we got an opportunity to preview Gaze UI, an interface that allowed us to navigate, zoom, select and scroll on a proprietary Windows 8-enabled laptop with just our pupils and a touchpad; this year, Tobii is introducing the REX, a USB-connected peripheral that adds these features to any Windows 8 PC. The device, slightly larger than a pen, adheres to the base of any PC monitor and can be integrated with other existing controls such as the keyboard, mouse or touchpad. Though this may sound quite similar to the PCEye launched in 2011, it's different in that the REX isn't intended for use as an assistive technology, so you'll still need to keep that mouse and trackpad around. Consumer pricing and availability haven't been announced, but Tobii plans to offer 5,000 units to consumers before the end of 2013; for developers, however, a special edition (seen above) should be available starting today for $995.