Apple continues to stockpile talent in augmented reality, an area that CEO Tim Cook has said is "incredibly interesting", as it looks like the company is working on some kind of display or technology that shows computer images superimposed on top of the real world.

This month, Apple hired Zeyu Li, who had worked at Magic Leap, the secretive augmented reality startup, for over a year. He's "interested in deep learning, VR, AR, driverless car," according to his LinkedIn profile.

In June, Yury Petrov started as a research scientist at Apple. Previously, he had worked at Oculus, Facebook's virtual reality platform, and taught at Northeastern University. "I am a specialist in experimental psychology, human vision, optics for head-mounted displays, brain imaging, and mathematical methods of signal processing and analysis," according to his LinkedIn summary. (Virtual reality immerses viewers in a 360-degree computer-generated world, while augmented reality simply superimposes images on the real world.)

Apple has a team of hundreds of staff building prototypes of potential headset configurations, the Financial Times reported in January.

Apple's hiring spree in this area really kicked off in May 2015, when it bought AR startup Metaio, an augmented reality startup. Metaio's CEO, Thomas Alt, still works at Apple, but he recently changed his focus from engineering to strategic deals. He is now a "director of procurement," according to his LinkedIn profile.


Meanwhile, iOS app developer Steven Troughton-Smith revealed that Apple has included several references to a "HeadMountedDisplayRenderingTechnique" in a key framework.

If Apple is indeed working on an AR device, it'll have a lot of competition. Google kicked off the commercial AR field with Glass, and the company hasn't entirely given up on the concept, although there are continued signs of disarray in the latest version of the project. Plus, Google is a big investor in secretive AR startup MagicLeap, Microsoft has HoloLens, and Snapchat is quietly working on its own AR glasses.

This story first appeared on Business Insider.