A blind woman can now see spots of light after being implanted with an early prototype bionic eye, confirming the potential of the world-first technology.
Australian researchers have been working for years to develop the bionic eye, in which electrodes are inserted into the retina of vision-impaired patients.
Dianne Ashworth, 54, was the first patient fitted with the device in surgery at the Royal Victorian Eye and Ear Hospital in May.
It was switched on last month at the Bionics Institute in East Melbourne after her eye had recovered fully from surgery, as researchers held their collective breath in the next room while watching via video link.
Ashworth said: "All of a sudden I could see a little flash ... it was amazing.
"Every time there was stimulation there was a different shape that appeared in front of my eye."
The electrodes send electrical impulses to nerve cells in the eye, which occur naturally in people with normal vision.
In the early prototype bionic eye, the electrodes are connected to a receptor fitted to the back of Ashworth's ear, which is then plugged in through an external wire to a unit in the laboratory.
Researchers in the laboratory use the unit to control the information sent to Ashworth's eye, allowing them to study how the brain reacts.
Feedback from Ashworth will allow researchers to develop a vision processor so they can build images using flashes of light.
Bionics Institute director Rob Shepherd said the next step was to test various levels of electrical stimulation.
"We are working with Ms Ashworth to determine exactly what she sees each time the retina is stimulated using a purpose-built laboratory at the Bionics Institute," Professor Shepherd said.
"The team is looking for consistency of shapes, brightness, size and location of flashes to determine how the brain interprets this information.
"Having this unique information will allow us to maximise our technology as it evolves through 2013 and 2014."
Working on the project is a consortium of researchers from the Bionics Institute, Centre for Eye Research Australia, technology research group NICTA and the Universities of Melbourne and New South Wales.
Chairman of Bionic Vision Australia David Penington said: "These results have fulfilled our best expectations, giving us confidence that with further development we can achieve useful vision.
"Much still needs to be done in using the current implant to build images for Ms Ashworth. The next big step will be when we commence implants of the full devices."
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