Stanford’s tiny eye chip helps the blind see again

A wireless eye implant developed at Stanford Medicine has restored reading ability to people with advanced macular degeneration. The PRIMA chip works with smart glasses to replace lost photoreceptors using infrared light. Most trial participants regained functional vision, reading books and recognizing signs. Researchers are now developing higher-resolution versions that could eventually provide near-normal sight.

Piyush Bhardwaj

10/24/20253 min read

Stanford’s tiny eye chip helps the blind see again

Date: October 22, 2025

Source: Stanford Medicine

News:

A Milestone in Restoring Functional Vision

The implant, named PRIMA and developed at Stanford Medicine, is the first prosthetic eye device to restore usable vision to individuals with otherwise untreatable vision loss. The technology enables patients to recognize shapes and patterns, a level of vision 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."

The research was co-led by José-Alain Sahel, MD, professor of ophthalmology at the University of Pittsburgh School of Medicine, with Frank Holz, MD, of the University of Bonn in Germany, serving as lead author.

How the PRIMA System Works?

The system includes two main parts: a small camera attached to a pair of glasses and a wireless chip implanted in the retina. The camera captures visual information and projects it through infrared light to the implant, which converts it into electrical signals. These signals substitute for the damaged photoreceptors that normally detect light and send visual data to the brain.

The PRIMA project represents decades of scientific effort, involving numerous prototypes, animal testing, and an initial human trial.

Palanker first conceived the idea two decades ago while working with ophthalmic lasers to treat eye disorders. "I realized we should use the fact that the eye is transparent and deliver information by light," he said.

"The device we imagined in 2005 now works in patients remarkably well."

Replacing Lost Photoreceptors

Participants in the latest trial had an advanced stage of age-related macular degeneration known as geographic atrophy, which progressively destroys central vision. This condition affects over 5 million people worldwide and is the leading cause of irreversible blindness among older adults.