According to results published October 20, 2025, in the New England Journal of Medicine, a newly developed, tiny, and wireless retinal implant device is helping restore vision in individuals with advanced age-related macular degeneration (AMD). AMD, which is the most common cause of permanent blindness in older adults and affects more than 5 million people worldwide, causes the central field of vision to become blurred as a result of the permanent damage to light-sensing cells of the retina called photoreceptors, as the condition advances. This new device, dubbed PRIMA (photovoltaic retina implant microarray)—a culmination of decades of development, prototypes, animal trials, and a small first-in-human trial—focuses on replacing the damaged photoreceptors that capture light and convert it into electrical signals that travel through nerve cells located at the back of the eye and through the optic nerve to the brain where images are formed. As a result, it has become successful in restoring the ability to perceive shapes/patterns, also known as form vision.
Originally developed by study co-leader Daniel Palanker, Ph.D., a professor of ophthalmology at Stanford University, the 2×2 millimeters and 30 micrometers thick implant placed at the back of the eye functions by converting light into electrical pulses that are meant to stimulate surviving retinal cells in the peripheral — a real-time camera built into specialized glasses being used to record images and sending them to the implant through the use of near-infrared light. Beyond assisting in restoring the transmission of visual information to the brain, users are able to adjust the zoom and contrast settings to improve their individual clarity. Unlike previous eye prostheses that required an external power source and cable running out of the eye, PRIMA’s photovoltaic nature allows it to require only light to generate an electric current — taking advantage of the transparency of the eye to deliver information by light.
An international, multi-center clinical trial co-led by Palanker, José-Alain Sahel, M.D. (chair of the Department of Ophthalmology at the University of Pittsburgh School of Medicine and author of the study), and Frank Holz, M.D. (professor of ophthalmology at the University of Bonn, Germany) sought to test PRIMA with 38 participants aged 60 and older at 17 medical centers in five European countries: France, Germany, Italy, the Netherlands, and the United Kingdom. Four to five weeks after implantation in one eye, participants began using the glasses — enabling some to make out patterns immediately, though the general visual acuity of all patients would improve over months of training. Two-thirds would report medium to high satisfaction with the device, with 19 experiencing side effects such as ocular hypertension (high pressure in the eye), tears in the peripheral retina, and subretinal hemorrhage (blood collecting under retina): none life-threatening and resolved within two months. After 12 months of use, all side effects in relation to the procedure resolved, and most by then were showing clear improvement in ability to identify letters on an eye chart — 81% improving by at least ten letters, the average participant improving by 25, and one individual improving by 59 (12 lines).
Of the 32 participants who completed the one-year follow-up, 26 (81%) experienced meaningful improvement in visual acuity, and 27 (84%) reported using the artificial vision to read numbers and words at home. In combination with the use of PRIMA’s digital enhancements, such as the zoom and contrast, these participants could read with an acuity equivalent to 20/42 vision.
While the device—originally developed by the Paris-based company Pixium Vision and later acquired by Science Corporation in 2024—has given some promising results, it is still only in its relative infancy. A questionnaire about users’ daily lives revealed no significant overall improvements, and an anonymous researcher would speak to Nature about his concerns that the lack of a control group doesn’t rule out the ability for improved results due to the intensive training and motivation from the exciting device. Currently, it can only provide black and white pictures, though grayscale and even colored advances are planned for the future. Additionally, being 100 micrometers wide with 378 pixels in each chip, the resolution is currently being sought to be improved, with a new, testing version on rats being as small as 20 microns wide with 10,000 pixels in each chip. As a result, co-leader Frank Holz looks to the future brightly, anticipating great improvements to the device that will yield even better results — this being only “the beginning of a journey.”
