We looked at Tobii's prototype eye-tracking technology at CES last year, but this year the company has taken it a step further. With a developer kit available for $995, it's still an expensive alternative to the keyboard / mouse, but similar to Leap Motion's alternative you can simply plug this in via a USB port to an existing Windows 8 PC. The Rex uses a stick-like device that you can mount underneath your monitor that will let you control a Windows PC with your eyes.

In practice it's working very well this year. We noticed last year that things weren't too smooth, but Tobii has clearly refined the technology ready for release. After a one time calibration, the Rex will automatically detect your eye movements. You simply look at what you want to launch with your eyes and hit a key on the keyboard so that the cursor clicks in that location. It's not fully eye controlled in that sense, but it works very well and each movement I attempted was accurate. Tobii had programmed its demo unit to use the insert key to scroll with your eyes, allowing me to scroll up and down by holding insert and simply looking in the direction I wanted to scroll in Internet Explorer.

Other use cases include the built-in Maps application for WIndows 8 where you can stare at a location and use the scroll wheel to navigate. In this particular instance, it seems just using the mouse might be easier, but you can start to imagine where this technology could really benefit users. Individuals with disabilities could control a PC with their eyes and simply trigger the click using a keyboard or even another method to simulate a key press. Tobii isn't shipping this to end users just yet, and pricing isn't set in stone, but it's improved from last year and I'm looking forward to seeing the final hardware later this year.