Restoring sight to the blind with cutting-edge brain implants

Horizon Magazine (EU), Anthony King, 22 August 2023.

• Berna Gomez, a former science teacher from Spain (57 in 2021), blind for 16 years, received an implant in the visual cortex: an array of 96 microelectrodes linked to a video camera on glasses. She could discern object outlines, identify left/right hand gestures and play maze-like video games. Implant (University Miguel Hernandez, Elche, Spain) was in place six months.
• Prof. Shih-Chii Liu (Institute of Neuroinformatics, University of Zurich) coordinates EU-funded project NeuraViPeR (CORDIS 899287, Sep 2020 – end Feb 2025): high-performance electrodes about four times thinner than a human hair, thousands of electrodes embedded in flexible strips; aims to increase resolution and reduce scarring/immune response.
• Liu: to discern a face or navigate a room, a blind person would need between 1,000 and 2,000 electrodes in the visual cortex. Normal vision has a resolution of ~1 million pixels.
• Prof. Peter Janssen (Leuven Brain Institute, Belgium) leads EU-funded project HyperStim (CORDIS 101071015, Nov 2022, four years): more sophisticated stimulation patterns to convey more information; goal: resolution at least 20x the number of electrodes physically present.
• Janssen: “The brain has to learn how to interpret the electrical stimulation.” Early users can expect a rough black-and-white image with contours/outlines.
• Context: Global Burden of Disease (2019) ranked vision impairment third-leading cause of years lived with disability; Europe has >2.5 million blind residents; ~40 million blind worldwide.