There was a time not too distant past when Kiwi eye doctor Thiran Jayasundera would be faced with telling patients when they would lose their sight for ever.
Then he found himself implanting bionic eyes - an astounding development in technology that has given hope to those who believed they would be blind forever.
Jayasundera, 42, is among the world's finest retinal specialists presenting at next week's Retina International World Congress in Auckland.
Auckland was home to Jayasundera just 10 years ago, before leaving for the United States where he continued to develop the skills that led to carrying out ground-breaking surgery.
In January 2014, he and his team at the University of Michigan's Kellogg Eye Center carried out the United States' first implantation of a bionic eye.
It was world-leading surgery, carried out on patient Linda Schulte who had endured 15 years of being blind through an inherited condition known as retinitis pigmentosa. The condition, for which there is no cure, causes cells in the retina to slowly die.
Through four-and-a-half hours of painstaking, exacting surgery, Jayasundera attached a 5mm computer chip worth around $200,000 to Schulte's retina.
He saw Schulte the day he spoke to the Herald on Sunday, and asked her husband Paul what difference it had made to his life.
"He said, one thing is it has made her a happier person." The happiness came through restored, restricted vision - seeing a grandchild run into a room, having a visual bond which was shared with others who were sighted.
For Jayasundera, that was fulfilment of the desire which led him to to Auckland Medical School.years earlier.
"I never imagined I would be doing this. I feel privileged."
Jayasundera was born in Sri Lanka, moving to New Zealand with his parents when he was 13. He attended New Plymouth Boys' High and then Auckland Grammar before attending medical school, inspired by family GPs from both Taranaki anbd the Queen City.
"This sounds cheesey, but just trying to help people appealed to me."
The Argus II - as the bionic eye is more properly called - sees 60 electrodes attached to the retina through which electrical impulses are sent. The chip receives those impulses from a video camera attached to a pair of glasses.
The impulses - potentially 60 pixels from the 60 electrodes - send signals to the brain which give a limited form of vision.
In high contrast situations, it might be shapes, or a "sparkle" the brain recognises as a particular object. "People are able to see the doorway, or to see pillars so they don't bump into things so much.
"A grandchild playing call - a patient might see a flickering light."
Jayasundera's current work, aside from surgeries which have now seen him implant the devices in 10 people, is focused on assessing who sight-restoring treatments should be given to and whether they have worked.
The developing science, meanwhile, is switching from mechanical to biological solutions - also a feature of the two-day conference next weekend.