Bionic Eye Restores Reading Vision for Patients Blinded by Macular Degeneration

Bionic Eye Restores Reading Vision for Patients Blinded by Macular Degeneration
by Sophie Jenkins
London, UK (SPX) Oct 21, 2025

A wireless bionic eye implant known as PRIMA has achieved what was once thought impossible - restoring central reading vision in people who were completely blind due to advanced age-related macular degeneration (AMD). The results, published in The New England Journal of Medicine, mark a watershed in the field of artificial vision, showing that patients with irreversible sight loss can once again read letters, numbers, and even words.

The multicenter PRIMAvera clinical trial enrolled 38 participants aged over 60 across 17 hospitals in the UK, France, Germany, Italy, and the Netherlands. Within months of receiving the implant, 84% of patients could identify text, and more than 80% experienced meaningful gains in visual acuity.

Restoring Sight Through Photovoltaic Vision

The PRIMA system consists of a tiny 2x2 mm photovoltaic chip - roughly the size of a grain of sand and half the thickness of a human hair - implanted beneath the retina. Working in tandem with augmented-reality glasses, the chip effectively replaces the light-sensing photoreceptors destroyed by macular degeneration.

A miniature camera on the glasses captures the visual field and projects it onto the implant using invisible near-infrared light. The chip then converts that light into tiny electrical pulses that stimulate the remaining retinal neurons, sending visual information to the brain. Patients perceive this as patterned, usable vision - the first time form vision has ever been restored in such cases.

"The device we imagined in 2005 now works in patients remarkably well," said Professor Daniel Palanker, co-senior author from Stanford University, who originally conceived the technology two decades ago. "We are the first to provide form vision rather than mere light perception."

Life After Darkness

Before treatment, most trial participants had total loss of central sight - unable to read, recognise faces, or even see the vision chart. After surgery and rehabilitation, many regained enough sight to read books, food labels, and even navigate public transport.

Sheila Irvine, one of the UK participants treated at Moorfields Eye Hospital, described the experience as transformative: "It's a new way of looking through your eyes, and it was dead exciting when I began seeing a letter. Reading takes you into another world - I'm definitely more optimistic now."

Patients reported using the device to perform everyday tasks, from solving crosswords to reading prescriptions. With digital enhancements such as zoom and contrast controls, some achieved acuity equivalent to 20/42 vision.

From the Lab to the Clinic

The operation, typically lasting under two hours, involves removing the eye's vitreous jelly and sliding the wafer-thin chip under the damaged retina through a tiny incision. Once the eye has healed, the system is activated and patients begin intensive visual rehabilitation to interpret the new artificial signals.

Unlike older retinal prostheses that required wired power, PRIMA's photovoltaic design runs entirely on light, enabling a wireless and fully self-contained implant. Patients retain their natural peripheral vision while using the prosthetic central vision, allowing both to merge seamlessly.

"No decline in peripheral vision was seen in the trial," said Mr. Mahi Muqit, associate professor at UCL and senior vitreoretinal consultant at Moorfields Eye Hospital, who led the UK arm. "Blind patients are actually able to have meaningful central vision restoration, which has never been done before. This represents a new era in artificial vision."

Clinical Outcomes and Safety

Of the 32 participants who completed a full year of follow-up, 27 regained reading ability and 26 showed measurable improvement in visual acuity - defined as gaining at least two lines on a standard eye chart. On average, patients improved by five lines, with one improving by twelve.

Nineteen patients experienced side effects such as ocular hypertension or subretinal bleeding, but nearly all resolved within two months.

"The results are something we couldn't have dreamt of when we started this journey 15 years ago," said Professor Jose-Alain Sahel, co-lead investigator and director of the UPMC Vision Institute. "More than 80% of patients were able to read letters and words - some even pages in a book."

A Platform for the Future

Currently, the PRIMA device produces black-and-white vision, but researchers are developing software to enable grayscale imaging - essential for face recognition, one of patients' top priorities. A next-generation chip featuring 20-micron pixels could deliver sharper detail and, with digital zoom, approach 20/20 vision.

"This is only the beginning," Palanker said. "We're already testing higher-resolution chips and new algorithms that could bring color, depth, and finer clarity to prosthetic vision."

Science Corporation, based in California, manufactures the PRIMA system and has now applied for regulatory approval in both Europe and the United States.

Hope for Millions with AMD

Dry age-related macular degeneration, particularly in its late stage known as geographic atrophy, affects more than 5 million people worldwide and currently has no approved therapy. The disease progressively erodes the macula - the retina's central region responsible for sharp, detailed vision - leaving only peripheral sight.

For those affected, the restoration of reading vision is a profound breakthrough. As Muqit noted: "These are elderly patients who went from being in darkness to being able to read again. Reading is one of the abilities people with vision loss miss the most. Now, for the first time, we can give it back."

Research Report:Vision Restoration with the PRIMA System in Geographic Atrophy Due to AMD