With its latest acquisition, Facebook is attempting to get a little more intimate with your facial expressions.

Oculus, the virtual reality company purchased by the social media company in 2014, has just acquired the Eye Tribe, a Danish eye-tracking startup. Details of the deal to buy the 16-person company were not disclosed.

The Eye Tribe demonstrated its technology on a modified Oculus headset at the Mobile World Congress in Barcelona in February, showing how it can enhance the gaming experience by signaling onscreen actions in response to where a gamer looks. But eye-tracking technology could come in handy at Facebook in a few other ways, too. Advertisers, the main source of the social network's revenue, could benefit from users' activity data (i.e., where their eyes focus onscreen and for how long). And in a video chat or presentation on, say, Facebook's new Workplace platform, it could be helpful for users to signal where on the screen they are looking at a given time.

Facebook isn't the only one getting into the nascent technology. In October, Alphabet Inc.'s Google bought another eye-tracking startup called Eyefluencer.

The acquisition of the Eye Tribe follows Facebook's purchases of facial recognition app IntraFace in November and motion sensor developer Pebbles in July. All three deals boost Facebook's giant step toward mainstream use of virtual reality tools.