A blind man who had an implant fitted to help restore his vision says it has failed, leaving him unable to see.
Chris James, from Wiltshire, lost his vision due to a condition known as retinitis pigmentosa, where cells at the back of his eye stopped working.
A 3mm-square chip was fitted to Mr James' eye in May 2012 allowing him to see some simple close-up shapes but it no longer works.
Surgeons said they expected the chip to fail within a year.
Mr James, a motor-racing enthusiast, wanted to be able to make out the silhouettes of different cars on the race-track.
"I was hoping to be able to go down to my beloved Castle Combe racing circuit and perhaps be able to tell the difference between a saloon car and a single-seater race car," he said.
"But unfortunately I wasn't able to make out the shapes of that.
"I went into it not knowing what to expect. I can't be disappointed as, obviously, if it doesn't work for me then maybe it'll work for someone else."