Tiny Implants, Big Gains: How Microchips Are Restoring Sight and Rewiring Medicine

Tiny Implants, Big Gains: How Microchips Are Restoring Sight and Rewiring Medicine

Alice Charton, 87, had spent a lifetime teaching children to read. Five years ago a hazy spot appeared in the center of her vision and spread into a blotch that made reading, recognizing faces, and navigating unfamiliar streets impossible. Doctors diagnosed age-related macular degeneration (AMD), a retinal disease that affects roughly 200 million people worldwide by damaging the macula — the part of the retina responsible for central vision. AMD rarely causes total blindness, but it can devastate day-to-day life.

The Prima Breakthrough

Three years ago, Charton regained a sliver of that lost world through an experimental system called Prima, developed by Science Corp., a San Francisco neuroscience company founded by biomedical engineer Max Hodak. Surgeons implant a 2 mm × 2 mm microchip — a tiny flake patterned with 400 hexagonal electrodes — onto the damaged portion of the retina. Patients wear chunky black glasses containing a small outward-facing camera that transmits images in infrared to the implant. Because the system uses infrared rather than visible light, it avoids interfering with patients’ remaining peripheral vision. The chip translates incoming impulses into signals delivered to the optic nerve and the brain, producing an approximation of central vision.

What appears barely visible to the naked eye has proven transformative. In a clinical trial published in the New England Journal of Medicine, 38 AMD patients across Europe received the Prima implant. Nearly 80% improved their eye-chart performance by at least 20 letters after surgery, and 84% could read letters, numbers, and words at home. Charton now reads an hour in the morning and an hour in the afternoon — modest gains, but life-changing.

“There is an eye chart that healthy people read at 4 meters; even at 1 meter, untreated patients can barely read the top line,” said Max Hodak. “In clinical testing of Prima, patients could read down to the fifth line.”

Where Prima Could Go Next

Daniel Palanker, who conceived the Prima idea in 2004 and consults on the project, says next-generation implants could increase pixel count from roughly 400 to about 10,000 by shrinking pixel size — potentially enabling visual acuity near 20/80, and with camera zoom, practical near-20/20 resolution in some circumstances. Science Corp. is also working on miniaturizing the bulky processing unit currently carried as a 2‑lb plastic “brick” into slimmer glasses temples for future releases.

Beyond Sight: Brain–Computer Interfaces (BCIs)

Science Corp. and many other companies are developing implants that interface directly with the brain. These brain–computer interfaces (BCIs) aim to restore function for people paralysed by stroke, injury, or neurodegenerative disease, enabling control of phones, wheelchairs, computers, household devices — and even the conversion of thought into synthesized speech. Hodak describes a “biohybrid” approach in which implants are seeded with stem cells that grow into brain tissue and forge connections with neurons, vastly increasing channel density and potential bandwidth for information exchange.

BCI development is widespread. The World Economic Forum estimates up to 680 companies operate in the space; the market was valued at $1.74 billion in 2022 and could reach $6.2 billion by 2030. Advocates foresee medical restorations — and eventual augmentation of healthy users (first responders, soldiers, or consumers) who might value faster, more direct interaction with AI or machine systems.

Notable Players and Progress

• Neuralink (Fremont, Calif.): Founded in 2016 and co-founded by Hodak, Neuralink has implanted devices in human trials (Prime), enrolling adults with quadriplegia. Its 1,024-electrode implant aims to enable cursor control and device operation by thought.
• Echo Technologies (UCSF): Led by Dr. Edward Chang, Echo’s wireless neuroprosthesis has enabled a paralyzed patient to convert thought into text and synthesized speech and to present an onscreen facial avatar; later work added bilingual toggling and improved hardware.
• Blackrock Neurotech: With more than 50 human implants and thousands of patient-days reported, Blackrock has used the Utah array — a 4 mm × 4 mm device with 100 needle probes — to let patients control cursors and prosthetics. The company reports emotionally powerful outcomes, including an ALS patient who spoke using a synthesized voice to his young child.
• Synchron: Uses a minimally invasive venous approach, threading a probe through arteries to place a listening device in a brain vein between motor cortices, avoiding open‑brain surgery.
• Paradromics: Developing high-channel approaches with thinner wires to reduce tissue injury and increase data throughput.

Technical and Biological Challenges

BCI systems face significant hurdles. Open-brain implants can cause infection, device malfunction, fibrous encapsulation around the chip, and cumulative tissue injury proportional to electrode count. The so-called “butcher ratio” describes how many cells are lost for every neuron recorded — a real concern as teams push electrode density higher. The Utah array, while proven, is sometimes criticized as an older design that is large and penetrating; alternative strategies include thin-film surface arrays that do not penetrate the cortex and venous approaches that avoid brain contact.

Science Corp.’s biohybrid approach adds complexity: stem-cell integration could enable far richer connectivity, but it also introduces risks of uncontrolled growth. The company says its design includes a pharmaceutical “kill switch” — the antiviral ganciclovir — to halt unwanted proliferation if necessary. Animal studies are underway; a cynomolgus monkey received a biohybrid implant last summer and is being monitored.

Ethics, Safety, Regulation, and Cost

BCI raises ethical and social questions about consent, privacy, dual-use (military or first-responder augmentation), and the potential for widening inequality if augmentation becomes available to those who can pay. Consent is particularly fraught for patients who may lose the ability to communicate; teams typically secure consent earlier in disease progression or rely on advance directives and family input.

Regulatory pathways are deliberate. Most U.S. trials proceed under FDA investigational device exemptions for Class III permanent implants, requiring long-term safety data and follow-up (commonly 12 months or more) before approval. Costs are expected to be high: Hodak estimates a Prima implant could cost in the $100,000–$200,000 range, reflecting substantial development expenses.

The Bigger Picture

BCI is at a pivotal inflection point. The technology promises life-changing medical benefits — restoring reading ability, enabling speech, returning mobility and communication — while also demanding careful attention to safety, ethics, and societal impact. Over the past 150 years, technologies have transformed daily life but remained external to our bodies; BCIs represent a new kind of fusion, where machines begin to integrate with neural tissue and become part of the person.

For Alice Charton, a tiny implanted chip returned the joy of reading. For millions more, the coming decades will determine whether brain‑computer interfaces deliver broad medical benefit, produce new forms of human augmentation, or require stricter guardrails to protect patients and society.

Write to Jeffrey Kluger at jeffrey.kluger@time.com.