Apple has recently bought SensoMotoric Instruments, a German company that makes eye-tracking glasses and platforms for both augmented and virtual reality. It’s not discussing the terms of the deal or long-term plans,  but the nature of SensoMotoric’s tech could hint at what Apple wants.

The glasses in question can follow your gaze in real time for all kinds of practical applications, such as improving athletic performance (by training athletes to focus on the right areas) or figuring out which store displays catch a shopper’s attention. In VR, you can use the eye tracking to either control the interface or minimize motion sickness.