On Oct. 20, 2025, a Stanford Medicine-led clinical trial that implanted a tiny wireless chip 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, 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 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.

The two-part device consists of a small camera, mounted on a pair of glasses, that captures images and projects them in real time via infrared light to a wireless chip in the eye. The chip converts the images into electrical stimulation, effectively taking the place of natural photoreceptors that have been damaged by disease.

The new trial included 38 patients older than 60 who had geographic atrophy due to age-related macular degeneration and worse than 20/320 vision in at least one eye. Four to five weeks after implantation of the chip in one eye, patients began using the glasses. Though some patients could make out patterns immediately, all patients’ visual acuity improved over months of training.

Of the 32 patients who completed the one-year trial, 27 could read and 26 demonstrated clinically meaningful improvement in visual acuity, which was defined as the ability to read at least two additional lines on a standard eye chart. On average, participants’ visual acuity improved by 5 lines; one improved by 12 lines.

The participants used the prosthesis in their daily lives to read books, food labels and subway signs. The glasses allowed them to adjust contrast and brightness and magnify up to 12 times. Two-thirds reported medium to high user satisfaction with the device.