A tiny chip placed under the retina gave back some central vision to people with an advanced form of macular degeneration, and new data suggest that sight is still there three years later. The results come from a European trial called PRIMAvera and were presented on October 11 at the 130th annual meeting of the American Academy of Ophthalmology, a large association of eye doctors.1 Among the patients tested at three years, vision with the device averaged about 20/120, compared with about 20/460 when the study began.1 The trial had no comparison group, and fewer than half of the patients who started were tested for vision at the three-year mark.1
What happened
The trial is testing a system called PRIMA in people with geographic atrophy, the advanced form of the dry type of age-related macular degeneration.1 In this disease, cells in the macula, the small part of the retina used for reading, recognizing faces and driving, wear away and leave a permanent blind spot in the middle of vision.2 Drugs approved in recent years can slow how fast the damage spreads, but none can restore sight that is already lost, according to the academy’s summary.1
The system has two parts. Surgeons place a wireless chip about two millimeters across, thinner than a human hair, beneath the retina where the light-sensing cells have died. The patient then wears glasses with a built-in camera. The glasses capture the scene and project it onto the chip as infrared light, and the chip turns that light into electrical signals that travel through the retina’s surviving cells to the brain.1 A 2024 conference abstract from the research team described the chip as 30 micrometers thick with 378 pixels, and said the infrared light used has a wavelength of 880 nanometers.3
The PRIMAvera trial enrolled 38 patients at 17 centers across Europe. After surgery, patients went through vision rehabilitation to learn how to use the device.1
The evidence so far
First-year results were published in The New England Journal of Medicine in 2025.1 Of the 38 patients, 32 were assessed at 12 months, and 81% of them reached what researchers count as a meaningful improvement in sharpness of vision.4 Patients improved by about five lines on a standard eye chart on average at one year.1
The new data cover the following two years. At the start, patients’ vision averaged roughly 20/460, worse than the 20/400 needed to read the big “E” at the top of an eye chart.1 Among the 18 patients evaluated at three years, vision with the device averaged about 20/120. That is a gain of nearly six lines, slightly more than at one year.1 Fourteen of the 18, or 78%, improved by at least two lines, which researchers consider clinically meaningful, and the same share improved by at least three lines.1
“We were very gratified to see that the remarkable gains we found at 12 months persisted through 36 months,” Dr. Martel said.
That is Dr. Joseph Martel, an ophthalmologist in Rancho Cordova, California, and the lead author of the three-year analysis.1
The researchers also looked at whether the implant harmed the vision patients still had. With the device switched off, sight in the implanted eye stayed essentially unchanged over three years, while vision in patients’ untreated eyes kept getting worse, as the disease usually does.1 The first-year report also said no participant lost side (peripheral) vision.4
On safety, most serious complications came in the first year and were linked to the surgery itself. Between month 13 and month 36, three patients each had one serious eye-related problem.1 The summary did not describe what those problems were.
Separately, a study published in June 2026 examined the eyes of two trial participants who had died, at 7 weeks and 18 months after implantation. The authors reported no significant inflammation around the chip and said the retina over it was viable and layered like nearby areas, with limited thinning in some spots at 18 months and a small scar where the chip was inserted.5 That is a look at two people only.
What it does not show yet
The trial had no control group, so there is no group of similar patients without the implant to compare against beyond each patient’s own untreated eye.1 At 36 months, 27 of the original 38 patients could be assessed for safety and only 18 for whether their vision improved. The summary did not say why the others were not assessed.1 The academy’s own release notes that if patients who did poorly were more likely to leave the study, the remaining group could make the device look more effective than it is.1
The vision the chip gives is also limited. The research team’s 2024 abstract described it as detailed “monochromatic” form vision, meaning shapes in a single shade rather than color.3 Vision was measured with the patient’s preferred electronic zoom at one meter.3 A score of 20/120 is still far from normal sight.
The three-year figures were presented at a meeting and summarized in a press release; they have not yet appeared as a full peer-reviewed paper in the sources reviewed here.1
Who is behind it
PRIMA is based on work originally done at Stanford University and is being developed by Science Corporation of California.1 The company is the trial’s sponsor.6 The device was previously developed by Pixium Vision of Paris.3 The 2024 abstract lists authors from the company, Stanford, Moorfields Eye Hospital in London, the University of Bonn, the University of Washington and the University of Pittsburgh, including José-Alain Sahel.3 The trial was co-led by Frank Holz of the University of Bonn, Yannick Le Mer in Paris and Mahiul Muqit of Moorfields.4 The 2026 tissue study notes that commercial disclosures appear in its footnotes, which were not part of the abstract reviewed.5
Dr. Martel said he hopes the data can support approval in the US so he can offer the device to his patients.1
How it fits the field
More than 5 million people worldwide have advanced macular degeneration, and it is the most common cause of irreversible blindness in older people, according to the academy.1 Most current and experimental approaches aim to slow the disease. Biohack recently covered a one-time gene therapy for geographic atrophy that started a large trial. The chip takes a different route: rather than protecting cells that are left, it tries to stand in for light-sensing cells that are already gone.1
The trial only took people aged 60 or older with geographic atrophy in both eyes and very poor central vision in the treated eye. People with a history of the “wet” form of macular degeneration or other serious eye diseases were excluded.2 Results may not apply to people outside those groups.
What to watch next
PRIMA received the CE mark in July, which allows it to be sold in Europe. It has not been approved in the United States.1 The company had applied for authorization in both Europe and the US.4 Dr. Martel said he looks forward to seeing the results repeated in real-world use in Europe.1
The trial is listed as active but no longer recruiting, with an estimated completion date of March 2029.2 Its registry record lists the main goals as the share of patients with meaningful vision improvement and serious side effects at 12 months, and no results had been posted there yet.6 Points to watch: a US regulatory decision, a full published report of the three-year data, an explanation of why many patients were not assessed, and how the device performs once doctors outside the trial start using it.
