Video game eye tracking, like the kind offered by Tobii’s various peripherals, is often a kind of superpower. You can tag enemies or aim a weapon simply by staring, or do things like shoot lasers with your eyes. But it’s also a way of taking power away from players, letting games use an almost involuntary motion to control your experience. Eye tracking company Fove, for example, created an interrogation scenario where you could reveal a comrade’s identity by staring at a photo too long. The brilliant 2015 horror game Soma, which recently added Tobii support, suggests more ways to turn the player’s own gaze against them — although like most eye tracking, it’s more of a subtle experiment than a killer new feature.

Soma is a first-person game where you play a seemingly ordinary man who wakes up in an underwater research facility full of eerily humanoid machines. You’ve got no weapons, so it involves a lot of sneaking, simple puzzles, and frantic sprinting. Eye tracking adds a few new elements. Most noticeably, your field of view shifts as you look around: if you stare at the left side of the screen, for example, your in-game “head” will turn a few degrees. If you’re using a flashlight, its light will follow your gaze. If you stare at some elements in the environment, you’ll get a slight zoom or other visual effect, like an important object gleaming. And if you look at enemies, they’ll react.

That last feature is by far the scariest, but it also seems like a slight tweak of an existing system. Soma’s monsters will already know if you’re “looking” at them with an old-fashioned mouse or analog stick, and the best way to survive is often to keep them totally out of your field of view — in which case the exact spot your eyes are pointed doesn’t matter. The effects and added movement make the visuals feel a little deeper, but I often forgot I had eye tracking turned on. Soma isn’t a game where you precisely figure out specific mechanics, either. It’s loose, narrative-focused, and unpredictable, so I wasn’t even sure when something was related to eye tracking and when it was simply an element I’d missed in my original playthrough.

Eye tracking isn’t common in VR yet, but it makes a lot of sense

This is the central quandary for Tobii. It can’t ask major developers to make games that wouldn’t work without eye tracking. But as an added feature, it’s not enough of a (literal) game-changer to justify buying a separate peripheral, and while some companies have built trackers into gaming laptops and monitors, it’s still not commonplace. Despite this, Soma is a great argument for how horror and eye tracking could work in another medium: virtual reality.

Eye tracking immediately makes more sense in a VR headset. It could let lower-powered systems support VR by allowing foveated rendering, which may be justification enough. VR games also offer peripheral vision in a way that flatscreen ones don’t, which gives players a lot more places to look. It allows for situations where totally turning away from a monster might actually be difficult, but keeping your eyes down is possible — an issue that came up in the PlayStation VR horror game Here They Lie. And if it becomes common, developers could explicitly build for it: imagine a game set in an oppressive society where you survive by avoiding eye contact. Soma studio Frictional has played with gaze-based interactions in several games, so I’d also love to see what it could do with the technology.

Unfortunately, eye tracking isn’t part of major VR headsets right now, although the HTC Vive is getting the feature as an add-on this year, and Tobii has worked with arcade-style VR platform StarVR. (Even if it were, VR is a niche genre in its own right.) People were writing about how eye tracking would revolutionize horror back in 2015, and it hasn’t happened yet. Maybe it never will, in its current state. Regardless of the future, though, I like the fact that things like eye tracking in Soma exist — and if nothing else, it reminded me exactly how scary the game still is.