20 years ago, James O’Brien endured something horrible: a corrosive acid substance was thrown in his face, leaving him permanently blind in one eye. Or at least, so he thought.

For the past 18 months, O’Brien has been undergoing pioneering treatment at London’s Moorfields Eye Hospital. There, surgeons have been using stem cells to replace the scar tissue over his eye. The result? O’Brien has regained the eyesight he once lost, opening up a world of opportunities for other victims who have also lost their ability to see.

The people over at the BBC documented O’Brien’s remarkable story and made a video that shows the surgeons that restored his sight. If you care to see it, follow the link right here.