Dan Scarfe was sad to see his 97-year-old grandfather sitting quietly in a room on Christmas Day, surrounded by his family, but unable to join in with conversation because of his hearing loss.

"It's got to the point now where he literally just sits in silence," said Scarfe. "And I thought, well, hang on a second. He watches TV all the time with subtitles. Why can't we subtitle the world?"

What seem like an ordinary pair of glasses are actually using Amazon Alexa software to turn incoming audio into closed captioning, before the software developed by Scarfe and his company Nreal project those CCs through augmented reality onto the world through the glasses.