Sony's virtual reality headset already stacks up nicely against the Oculus Rift, but the company could also have a secret weapon. Last year, Sony revealed it was working on technology to let you control games with your eyes — technology that we just tried here at the 2014 Game Developers Conference. The same Sony team behind the Project Morpheus VR headset, the PlayStation Move, and the PlayStation Camera are also showing off a modified version of Infamous: Second Son where your eyes control where your character is looking.

With a special camera and software from SensoMotoric Instruments, setup is a breeze — you simply look at two different points on the screen — and then whenever you look at anything in the game, the camera rotates to center it in your view. We actually found it quicker and more accurate to aim at things than with the analog stick itself, no mean feat, and we were quickly wreaking havoc by throwing fireballs with pinpoint precision at traffic signs, trash cans, and the occasional enemy.

There are plenty of caveats, of course, like how difficult it is to keep the camera still and take in a scene, and how long it takes to quickly turn 180 degrees, but Sony's demo let us use a DualShock controller and eye-tracking simultaneously. There's also the matter of size and cost, as the depth camera used here is Kinect-sized and designed for professional use.

However, Sony's Eric Larsen says that the company believes it could actually miniaturize the components and bring down the price enough that eye-tracking could fit in a virtual reality headset like the Morpheus, which could create some exciting possibilities. In addition to controlling a character, eye-tracking inside a VR headset could theoretically be used to further enhance the player's sense of presence by faking depth of field, allowing your eyes to "focus" on virtual objects similarly to the way they focus in the real world. It also could allow game developers to explore mechanics where the player needs to avoid looking at certain things, like the bombs in the eye-tracking game of Fruit Ninja we played two years ago.