This could be as big as the smartphone, according to Apple CEO Tim Cook.
Apple has acquired SensoMotoric Instruments, a company that specializes in eye-tracking technology useful for virtual reality (VR) and augmented reality (AR) applications.
SensoMotoric, founded in 1991 in Teltow, Germany, helps power devices, like glasses and headsets, that can follow people’s gaze. The company has worked with Facebook’s fb Oculus Rift VR kit and RedBull’s e-sports lab in recent years.
An Apple aapl representative essentially, albeit not officially, confirmed the purchase in a statement provided to Fortune. “Apple buys smaller technology companies from time to time, and we generally do not discuss our purpose or plans,” the rep said, employing a comment that Apple typically uses when all but affirming an acquisition.
Get Data Sheet, Fortune’s technology newsletter.
The news was first reported Monday by the Apple blog MacRumors, which discovered the signature of Gene Levoff, Apple’s vice president of corporate law, on a legal document related to SensoMotoric’s acquisition. Subsequently, Axios, a media startup, received the first confirmation from an Apple rep.
Apple CEO Tim Cook has previously compared AR’s potential to that of the smartphone. Cook’s praise is notable given the importance of the iPhone to Apple’s business, helping it attain the title of the world’s most valuable company in terms of market capitalization.
Earlier this month at its worldwide developer’s conference (WWDC), Apple released ARKit, a software kit that enables developers to overlay AR holograms on the real world through their phones.
Eye-tracking tech is poised to be a vital element for companies to master in their race to make AR consumer-friendly. Last year, Apple’s rivals, Facebook and Google, made acquisitions similar Apple’s most recent one, buying startups such as The Eye Tribe and Eyefluence, respectively.