Snap is clearly determined to protect the technology behind its Spectacles with built-in augmented reality. The Verge has confirmed that Snap has bought WaveOptics, the company responsible for the Spectacles' AR displays. The deal is worth over $500 million, but won't preclude WaveOptics from supplying its waveguides to other companies even as it develops new components for Snap.
The buyout is Snap's largest to date and reflects the company's commitment to wearable AR. It has been developing Spectacles for years, with three generations of publicly available (if sometimes hard to get) models. This suggests that Snap has no intention of slowing development any time soon, and might ramp things up.
And like The Verge notes, there's also a defensive motivation at work. Apple bought waveguide marker Akonia in 2018 to help develop its long-rumored AR headset, while Facebook and Google are developing waveguides of their own for future AR glasses. Snap's deal prevents WaveOptics from falling into the hands of a rival that would promptly end outside sales.