For nearly four years, a 65-year-old man lived in complete darkness. An eye disease had damaged both of his optic nerves, leaving him totally blind and even unable to detect the presence of light.

During an experimental brain-computer interface (BCI) trial, that changed. The study was led by researchers from Spain's Miguel Hernández University and Hospital Vega Baja.

Researchers implanted an invasive neural device – an array of 100 microelectrodes – into his visual cortex, the region of the brain responsible for processing sight. The goal was not to restore natural vision, but to generate artificial flashes of light by electrically stimulating the brain. 

Instead, after electrical stimulation sessions began, the man started to perceive movement and light. In tests, he was able to indicate the position of objects and imitate arm movements shown in front of him.

The findings were published on February 3 in Brain Communications, though the underlying mechanism remains unclear.

For now, the visual recovery remains an isolated case. But it highlights the medical potentials of BCI technology, which is being developed to help people regain movement, restore vision or hearing, and treat neurological disorders.

Neuralink is working in similar directions. One implant is designed to help people with paralysis move again, another aims to restore sight and a separate program focuses on treating neurological diseases. In 2023, Neuralink completed the world's first human BCI implant.

China has stepped up its efforts in 2025.

In May 2025, researchers completed the first invasive BCI clinical trial in China, helping a quadruple amputee regain basic daily living abilities. The implant was developed by Chinese company StairMed. 

According to the company, its neural electrodes are about one-hundredth the width of a human hair. The cross-sectional area is roughly one-seventh to one-fifth that of Neuralink's electrodes, and their flexibility is more than 100 times greater, which could reduce brain tissue damage. By 2025, StairMed had completed three invasive clinical trials, achieving stable robotic arm control.

Chinese companies are also pursuing more specialized neurological applications. For instance, Neuracle's NEO system targets drug-resistant epilepsy and related conditions. Rishena's CNS system has demonstrated medical improvements for Parkinson patients.

Invasive BCIs are moving closer to scaled production, accompanied by rising investor interest.

Elon Musk said on X that Neuralink plans to start high-volume production of its BCI devices in 2026. In June 2025, Neuralink raised $650 million in a Series E round, valuing the company at $9 billion, one of the largest single financings in the sector.

In January 2026, Chinese company BrainCo secured approximately 2 billion yuan ($280 million) in equity financing, marking the largest single funding round in China's BCI industry.

At the same time, non-invasive approaches are advancing rapidly.

BrainCo has developed a bionic hand that allows amputees to control a prosthetic limb without surgery. Tianjin University's Brain-Computer Interaction and Human-Machine Fusion Haihe Laboratory has introduced non-invasive BCI exoskeleton devices to assist stroke patients in regaining arm and hand function, helping more than 3,000 patients.

In January 2026, OpenAI founder Sam Altman co-founded BCI startup Merge Labs, which is pursuing a ultrasound-based approach aimed at imaging and modulating brain regions without implantation.

According to a report released by the China Academy of Information and Communications Technology, the global BCI market is already worth tens of billions of dollars and is projected to exceed $100 billion by 2030.