Facebook’s vice president of AR and VR Hugo Barra is leaving the company, he announced (where else) on Facebook Monday.

“Today is my last day at Facebook Reality Labs, after 4 years working on projects that have been more exciting and more challenging than anything I’ve encountered in my career, with some of the brightest minds and kindest people I’ve ever had the pleasure to meet,” Barra wrote in the post. He said he planned to “explore the healthcare technology space,” so he could apply what he had learned in consumer tech to solve problems in health care. “I believe society is still poorly equipped with the tools people need to really understand our health and gain control over our health outcomes,” he wrote.

After serving as Google’s vice president of Android product management and then several years at Xiaomi, Barra joined Facebook in 2017 to run its Oculus VR team. In 2019, he moved to his current role, tasked with “building a global AR/VR partner ecosystem” based in New York City, which eventually became part of Facebook Reality Labs.

Barra is leaving Facebook before the company launches its first pair of consumer “smart glasses,” which it said last year would be a branded Ray-Ban product. He touted the project on Twitter last September and mentioned the launch in his farewell note (but didn’t provide details about a release date other than “this year”). Barra said development of the smart glasses became “his main focus at Facebook.”

But after announcing in September that the smart glasses were coming sometime in 2021, Facebook tried to temper expectations about the smart glasses; in March, CFO David Wehner said at a conference that the glasses wouldn’t be close to the technology Facebook eventually hopes to achieve in AR.

Facebook CEO Mark Zuckerberg thanked Barra for his work in a comment on Barra’s Facebook post: “Thanks for everything you’ve done to help build the next computing platform and the whole ecosystem around it,” Zuckerberg wrote. “I’ve learned so much working with you, and I’m excited to see what you build next.”