Edge went hands on with Switchback and has this to say:
"It's an eye-tracking feature, though, that lingers longest after our demo. A door painted with the instruction "don't blink" opens up into a room of blood-smeared mannequins in harlequin masks, their bodies twisted into unnatural poses. Eventually we can't help it any more, and let our eyelids flutter closed. When they open again, the mannequins have been rearranged - or have rearranged themselves. Another blink, and it happens again, except that one of them has now come to life. As we repeat this process, we learn to use our eyes tactically, only blinking once our guns are readied. It's a strange, startling application of the tech."