A blind mother-of-two has spoken of her joy at being able to see her children and tell the time for the first time in more than five years after being fitted with a "bionic eye."
Rhian Lewis said it "felt like Christmas Day" when she realised she could tell the time following the retinal implant at Oxford's John Radcliffe Hospital.
As part of an ongoing trial at the hospital, surgeons implanted a tiny electronic chip at the back of her right eye's retina in a bid to help her see.
The 49-year-old, from Cardiff, has suffered from retinitis pigmentosa - an inherited disorder - since she was five.
The condition, which has no cure, causes gradual deterioration of the light-detecting cells (photoreceptors) in the retina, which can lead to blindness.
During follow-up tests after the implant, Miss Lewis was asked to look closely at a large cardboard clock to see if she could tell the time correctly.
She had not been able to tell the time with her right eye in 16 years and for about six years with her left eye.
Speaking of the moment she realised she could read the clock, Miss Lewis said: "Honest to god, that felt like Christmas day."
The implant - a 3mm sq array of around 1,500 light sensors which sends pulsed electrical signals to nerve cells - is connected to a tiny computer that sits underneath the skin behind the ear.
This is powered by a magnetic coil on the skin. From the outside, it looks like a hearing aid.
When the device is first switched on, patients see flashes of light, but over a few weeks the brain learns to convert those flashes into meaningful shapes and objects.
Describing the moment the device was turned on, Miss Lewis said: "They said I might not get any sensation and then all of a sudden within seconds there was like this flashing in my eye, which has seen nothing for over 16 years, so it was like, oh my god, wow!"
When she was taken out to test the implant, Miss Lewis said: "The first thing I thought 'there might be something there,' there was a car, a silver car, and I couldn't believe it, because the signal was really strong, and that was the sun shining on the silver car.
"And I was just, well, I was just so excited, I was quite teary.
"The enormity of it didn't hit me until I'd actually got home, thinking 'Oh my god, what have I done? I've actually spotted something out that I haven't been able to do'."
Miss Lewis is the first patient outside of Germany to be implanted with a newer, second-generation device.
Professor Robert MacLaren, who is leading the research at Oxford, said: "It's an amazing process because what Rhian and others are trying to do is reactivate a part of the brain that hasn't been doing anything for the last 10 years or so. There is a lot of rehabilitation because basically they are learning to see again."