While most of us are happy just to avoid Luigis death stare, how you look at the screen apparently has a big bearing on your gaming prowess. SteelSeries has just launched a new device to give you an edge in that regard, the Sentry Eye Tracker. Created in partnership with Tobii Technology (which previewed the tech at CES 2014 in January), the product uses eye-tracking strictly for coaching, rather than gameplay.