Google has hinted that the company's much-maligned Google Glass headset could one day make a comeback as "augmented reality" technology improves.
Rick Osterloh, the head of Google's hardware division, said hi-tech glasses were "very interesting to us", although he admitted it would be years before they would become a mass market product.
Google first released its camera-equipped glasses, which featured a screen for reading texts and discretely watching videos, to the public in 2014. They sparked a privacy backlash and Google cancelled the project a year later, with the scheme ranking as one of the company's major failures.
However, recent technological advances have reignited interest in augmented reality headsets.
Intel and the secretive US start-up Magic Leap are both working on holographic glasses while Microsoft's HoloLens went on sale in 2016. Apple is also rumoured to be developing its own device.