Allen Zderad, from Minnesota in the US, has the degenerative eye disorder retinitis pigmentosa and had lost almost all of his vision by 2005, only being able to detect very bright light. The 68-year-old underwent a procedure to have the Argus II implant from Second Sight.
Retinitis pigmentosa is an inherited condition in which the photoreceptors of the retina degrade and die over time. The cell death causes increasing loss of vision, and may eventually lead to blindness.
The retinal implant works by stimulating the remaining healthy cells of the retina and works in conjunction with a computer pack and video glasses, transmitting visual signals to the ganglion cells of the eye.
With the device switched on, the implant will enable Mr Zedrad to navigate his surroundings, however, he will not be able make out the details of faces.
“It’s a pulsing light, it’s not like regular vision where it’s constant,” said Mr Zderad. “It’s crude, but it’s significant,” he added.
Researcher and ophthalmologist, Dr Raymond Lezzi, from the Mayo Clinic in Rochester, Minessota, was present during the trial.
Dr Lezzi said: “What we’re trying to do is replace the function of the lost photoreceptors with the retinal prosthesis.”
Following the trial, Dr Lezzi added: “This is great for this family. It’s also very unusual for a scientist like me to be able to actually apply outcomes of what we’ve worked on for years to help a patient. That’s very special.”
The clip below shows an emotional Mr Zedrad reacting to the device being switched on, and seeing his wife.