At a certain point during my meeting with Tobii, I decide that the unassuming Swedish eye tracking company has some of the creepiest tech at CES. Putting on glasses fitted with tiny cameras, I look around a hotel suite — focusing in turn on the raised hand of Tobii Tech president Oscar Werner, the camera in front of me, a tablet, and a promotional pamphlet. As I read the pamphlet, I become keenly aware of the fact that these glasses can tell exactly how my eyes are moving. I run my them along the lines of text with exaggerated speed and motion. I'm reading fast! my eyes say. And paying attention! Once I'm done, I don't remember a word.

"What you look at is a good approximation of what you think," says Werner afterwards. "So this is a tool to understand true human behavior." Tobii sells the glasses for things like training and market research; among other things, says Werner, chef Jamie Oliver used them to show how many sugary treats stores place at a kid's-eye level. Stripped of this valuable context, though, they're an unintentionally dystopian surveillance device — I realize later that my attempt at reading basically reenacted a scene from Snow Crash.

"What you look at is a good approximation of what you think."

But this isn't, I imagine, why most casual visitors check out the company. After MSI announced the first laptop to feature Tobii's built-in tracking tech, they're probably there for a futuristic version of Assassin's Creed Syndicate that uses eye movement to target enemies, aim a grappling hook, and mark objectives. It's hard not to make eye tracking feel like a bit of a gimmick, especially because Tobii support is an add-on rather than a part of the initial game design process. But it's an add-on that mirrors something we already do. Instead of looking at a point and then moving an analog stick to match your view, Tobii does the work for you. It's a small change, but a clever one — as is the Grand Theft Auto V mod that lets you target cars with your eyes and shoot rockets at them.

This is the contradiction of Tobii. It's a company known among consumers for small game interface tweaks, but its technology monitors something that, once you start thinking about it, is deeply personal. Our eyes reveal what we think is important, even when the rest of our body language is trying to hide it. They don't just control grappling hooks, they control which parts of the world we're aware of.

If there's a place where these two threads combine, it could be virtual reality. "I think eye tracking is a necessary component for VR to succeed in a major scale," says Werner — a sentiment shared by some other headset makers. Virtual reality cuts our eyes off from the rest of our senses and drops them into a different world. Tracking gives us a more direct way to interact with that world, and it potentially makes it easier for computers to render. A technology called foveated rendering can dramatically strip down a virtual environment, only fully detailing the places we're looking.

So far, Tobii has announced one partnership with a company called Starbreeze, which is integrating eye tracking into its StarVR headset. At CES, though, it's still showing off parts: a pair of little cameras, a plastic eyepieces, and a chip mounted in lucite. The future, it seems, is still too far away to see.