Eye prosthesis is the first to restore sight lost to macular degeneration
In a Stanford Medicine-led clinical trial of a wireless retinal prosthesis, people with advanced macular degeneration regained enough vision to read books and subway signs.
Left: Simulation of a patient’s vision with macular degeneration.
Right: Simulation of the patient’s vision enhanced with the PRIMA eye prosthesis.
Credit: Palanker Lab
A tiny wireless chip implanted in the back of the eye and a pair of high-tech glasses have partially restored vision to people with an advanced form of age-related macular degeneration. In a clinical trial led by Stanford Medicine researchers and international collaborators, 27 out of 32 participants had regained the ability to read a year after receiving the device.
With digital enhancements enabled by the device, such as zoom and higher contrast, some participants could read with acuity equivalent to 20/42 vision.
The results of the trial were published Oct. 20 in the New England Journal of Medicine.
The device, called PRIMA, developed at Stanford Medicine, is the first eye prosthesis to restore functional sight to patients with incurable vision loss, giving them the ability to perceive shapes and patterns — also known as form vision.
“All previous attempts to provide vision with prosthetic devices resulted in basically light sensitivity, not really form vision,” said Daniel Palanker, PhD, a professor of ophthalmology and a co-senior author of the paper. “We are the first to provide form vision.”
Read the full story via the Stanford School of Medicine's website, written by Nina Bai.
Learn more
Read Palanker's paper on the PRIMA device results, published October 20, 2025 in the New England Journal of Medicine.
About Daniel Palanker, PhD
Daniel Palanker, PhD, is a professor of ophthalmology and, by courtesy, of electrical engineering at Stanford University.
Palanker is working on optical and electronic technologies for diagnostic, therapeutic, surgical and prosthetic applications, primarily in ophthalmology. In the field of biomedical optics, these studies include interferometric imaging of neural signals and cellular physiology. In the field of electro-neural interfaces, Dr. Palanker is developing retinal prosthesis for restoration of sight to the blind and implants for electronic control of organs. View his Stanford profile.
Media inquiries
Janice Turi
Web and Communications
Department of Ophthalmology | Stanford University
Byers Eye Institute at Stanford
E: jturi@stanford.edu