Surgeons at Manchester Royal Eye Hospital are looking for patients willing to be fitted with a bionic eye.
The technology, which consists of an electrode panel replacing the retina at the back of the eye, is being tried out on two local patients.
Suffering from the degenerative disease retinitis pigmentosa, they have lost most of their sight.
The consultant ophthalmologist leading the process wants more participants to take part in the pioneering treatment.
The patients must wear glasses which have a camera and a transmitter fitted to them.
The camera transmits a wireless signal to the electrode panel fitted behind the eye, the electrodes then stimulate the remaining retinal nerves which send a signal along the optic nerve to the brain.
Paulo Stanga, the consultant ophthalmologist leading the investigation, wants more participants who have a confirmed history of retinitis pigmentosa.
He said: "We are very encouraged by the trial's results so far - the bionic eye operations went exactly according to plan and both patients are doing well.
"We hope the implant will improve each patient's orientation and mobility, spatial localisation and motion detection.
"The trial remains inspiring in terms of presenting a very real and tangible step forward in treating people with total vision loss."
Ron, 73, who had the surgery in London's Moorfields Eye Hospital, last year told the BBC it had made a big impact on his life.
"For 30 years I've seen absolutely nothing at all, it's all been black, but now light is coming through. Suddenly to be able to see light again is truly wonderful."
For more information contact the British Retinitis Pigmentosa Society at www.brps.org.uk.