For the first time ever, real-life trials have shown that sight can be restored to the totally blind, thanks to an electronic retina.
Chris James and Robin Millar were both able to detect light immediately after their operations, and are now beginning to regain useful vision. Their operations were carried out at the Oxford University Hospitals NHS Trust and King’s College Hospital in London.
The 'bionic eyes' were developed by Germany's Retina Implant, which two years ago trialled them in a laboratory setting. The new recipients, though, have a portable device that can be worn in day-to-day life. It's being tested in Germany and China too.
James and Millar suffer from retinitis pigmentosa, an inherited condition that affects around one in every 3,000-4,000 people in Europe. It's a progressive disease, with light-detecting cells in the retina deteriorating over time.
But the new chip aims to replace the lost cells in the retina with 1,500 tiny electronic light detectors. It's implanted below the retina, and delivers electronic signals to the optic nerve and thence the brain. It's attached to a small control device that sits behind the ear.
"What makes this unique is that all functions of the retina are integrated into the chip. It has 1,500 light sensing diodes and small electrodes that stimulate the overlying nerves to create a pixellated image," says Robert MacLaren, professor of ophthalmology at the University of Oxford, who led tyhe surgical.
"Apart from a hearing aid-like device behind the ear, you would not know a patient had one implanted."
Chris James, 54, was left completely blind in his left eye in 2003, after years of deteriorating eyesight. His right retained the ability to detect strong lights.
But with the new implant in his left eye, he's now able to recognise a plate on a table and other basic shapes - and his vision is continuing to improve.
"I’m still getting used to the feedback the chip provides, and it will take some time to make sense of this," he says.
The electronic retina could become a standard treatment for patients with retinitis pigmentosa, says Professor Maclaren.
But, he warns: "The device is not suitable at present for age-related macular degeneration, but advanced cases may benefit from it in future. It is not suitable for diseases that affect the optic nerve, such as glaucoma."