Five to 10 years. That’s how long Michael Abrash, chief scientist at Facebook, predicts it will take before augmented reality glasses—which will display digital images and data on wearable devices that people view through—are ready for the masses.

Abrash leads Facebook Reality Labs, a Redmond, Washington–based research group that includes teams of academics and engineers working on new generations of consumer hardware devices, including virtual reality and AR products. His cautious timeline for AR eyewear reflects a series of technical breakthroughs in everything from batteries to user interfaces that will need to happen before large numbers of people are willing to wear computers on their faces.