People who had completely lost their vision to eye diseases with age read books again thanks to an electronic eye. Video captured by glasses-mounted cameras was delivered to the brain through an electronic chip implanted in the retina. Patients read hospital prescriptions and food labels and even checked subway maps. Because it is wireless and needs no battery, it was hailed as a breakthrough with strong commercial potential.
A research team led by Daniel Palanker of the Stanford University School of Medicine's Department of Ophthalmology said in the New England Journal of Medicine (NEJM) on the 20th (local time) that an ultraminiature wireless chip implanted behind the eye and advanced glasses partially restored vision in patients with advanced age-related macular degeneration (AMD). According to the team, 27 of 32 patients who had completely lost vision regained the ability to read one year after receiving the implant.
◇Vision recovered from 0.06 to 0.47
Age-related macular degeneration occurs when the retinal pigment epithelium, which supports and nourishes photoreceptor cells, is damaged with age. The eye focuses light reflected from objects through the lens onto the inner retina. There, photoreceptor cells convert light into electrical signals so the brain can recognize objects. When retinal cells are damaged, vision deteriorates and, in severe cases, leads to blindness. It affects 1% of people age 50 and older, but there is no fundamental cure.
The research team conducted clinical trials on 38 patients aged 60 or older with advanced age-related macular degeneration at 17 hospitals in the United States, the United Kingdom, France, Germany, and Italy. The patients' vision was worse than 20/320 by U.S. notation. That means what a person with normal vision can see at 320 feet (98 meters) is only visible at 20 feet (6 meters). By Korean notation, this corresponds to 0.0625, a visual impairment level. Central vision, which looks at the center of the field, was completely lost.
The clinical results were remarkable. Of the 32 who completed the one-year trial, 27, or 84%, could read letters and numbers. On average, patients could read five lines on a vision chart. One person read up to 12 lines. The team said, "In particular, the PRIMA device's glasses can adjust brightness and magnify up to 12 times," adding, "Through this, some patients improved to 20/42 (0.47 by Korean notation)."
The electronic eye changed patients' daily lives. Patients with the electronic eye read books, hospital prescriptions, food labels, and subway maps. The research team at University College London (UCL), which conducted the U.K. trial, said, "Regaining the ability to read greatly improves quality of life and helps restore confidence and independence."
Nineteen participants experienced side effects such as ocular hypertension, peripheral retinal tears, and subretinal hemorrhage. But there were no dangerous cases, and nearly all symptoms resolved within two months, the team said.
◇Restoring photoreceptor function with a wireless electronic chip
Palanker's team developed a new electronic eye called PRIMA for more than 20 years for patients who had completely lost vision due to age-related macular degeneration. The name comes from the initials of "photovoltaic retina implant microarray." As the name suggests, it is a chip that receives light in the retina and generates electricity.
PRIMA consists of glasses-mounted cameras, an electronic chip, and a portable computer. The camera sends information about what it sees to the implanted retinal chip using an infrared laser. The portable computer worn at the waist uses artificial intelligence (AI) to process the camera feed so the chip can recognize it. The retinal chip converts light into electrical signals and sends them to the brain. The brain then recognizes objects as before.
The electronic chip, 2 mm on each side, is implanted in the retinal area where photoreceptors are damaged. At 30 μm (micrometers; 1 μm is one-millionth of a meter) thick, it is about half the thickness of a human hair. Patients received training to see the world with the electronic eye starting one month after surgery.
The electronic chip can be considered a kind of electronic photoreceptor. The difference is that real photoreceptor cells respond only to visible light, while this chip accepts only infrared light coming from the patient's glasses. The chip's response to the laser's infrared light was the result of the team's consideration for patients.
Patients with macular degeneration have completely lost central vision, which looks straight ahead, but retain peripheral vision that can see some of the outer field. Palanker said, "The retina's peripheral vision continues to detect visible light as is, while central vision is restored with infrared," adding, "By integrating artificial vision with remaining peripheral vision, patients can make the most of their sight."
◇No battery needed, offering strong commercial potential
There had been previous attempts to restore vision by implanting electronic chips in the retina. But they had to receive power from outside and required consolidation by wires. By contrast, the PRIMA chip operates wirelessly by generating current from light, the team said. That makes it convenient to use and suggests strong commercial potential.
The team said it will further improve the resolution of the electronic eye. The current implanted chip has a resolution of 378 pixels. That means the visible image has 378 pixels horizontally and vertically. The team said it will reduce pixel pitch from 100 μm to 20 μm, increasing to 10,000 pixels per chip.
Palanker said, "A 20 μm pixel chip could provide patients with 20/80 (0.25 by Korean notation) vision," adding, "Using the magnification function of the glasses-mounted camera, patients could achieve near-normal 20/20 vision."
References
New England Journal of Medicine (2025), DOI: https://doi.org/10.1056/NEJMoa2501396
Ophthalmology Science (2024), DOI: https://doi.org/10.1016/j.xops.2024.100510
Nature Photonics (2012), DOI: https://doi.org/10.1038/nphoton.2012.104