A pair of AI glasses gives 5 million blind people hope of seeing again.

People who have been blind for many years can regain their sight.

I always thought this technology would come one day, but I didn't expect it to become a reality now.

Left: Simulation of the vision of patients with visual impairment. Right: Simulation of the vision of patients after the research invention.

This research was led by Stanford University and jointly completed with Science Corporation, founded in 2021 by brain-computer interface entrepreneur Max Hodak (co-founder of Musk's Neuralink). It was published in the world's top medical journal, the New England Journal of Medicine (NEJM).

They recruited 38 patients with advanced AMD (Age-related Macular Degeneration), in whom the photoreceptor cells in the central retina had completely died.

The doctor holds the chip implant

By implanting a tiny chip, only 2 millimeters wide and 30 micrometers thick, smaller than a grain of rice, called PRIMA (photovoltaic retina implant microarray), it can replace the dead photoreceptor cells and start working again.

The results showed that one year after device implantation, up to 80% (26 out of 32 evaluable participants) had a clinically significant improvement in vision, with an average of more than 25 additional letters recognized on the eye chart.

It sounds like a movie plot, but it really happened.

How does a 2mm-wide chip enable people to see again?

To understand how the chip works, we first need to know what the disease targeted by this research, age-related macular degeneration (AMD), is and why it causes people to lose their sight.

Simply put, the clearest and most central vision of the human eye is achieved by the photoreceptor cells (cone cells) in the macula.

When light enters the eye, it passes through the iris to the retina. The image is focused on the retina and converted into electrical impulses, which are transmitted to the brain by the optic nerve, ultimately resulting in the perception of an image.

However, in AMD patients, the cells responsible for "converting light into electrical impulse signals" gradually die. As a result, the process of seeing is interrupted.

People can still see light and shadows in the periphery, but there is a fixed black spot in the center;

In severe cases, they are unable to read, recognize people, drive, or watch TV;

Currently, approximately 5 million people worldwide are blind due to this condition.

Simulation of reading with age-related macular degeneration, with a large black shadow in the middle

What's more cruel is that once these cells die, they won't grow back. This is why all previous treatments could only do one thing: slow down the deterioration, rather than enabling people to see again.

Until this chip appeared.

In AMD, the photoreceptor cells die, but the neural network remains intact. This means that although the light signals from the outside world cannot be converted into electrical signals, electrical signals can still be transmitted to the brain.

So, scientists came up with a very clever idea: bypass the photoreceptor cells and directly input electrical signals into the nerves. This chip, called PRIMA (Photovoltaic Retina Implant Microarray), is like embedding a "camera + electrical signal trigger" into the human eye.

Comparison of retinal imaging scans before (AC) and after (BD) chip implantation

This system consists of three parts:

1. Glasses with a camera, which capture external images, similar to a camera. (Parts 2 and 3 in the figure, where 2 is the sunglasses lens)

2. A pocket processor that transmits the images captured by the camera to the chip via infrared light. (Parts 1 and 4 in the figure, where 1 can be used to adjust brightness and zoom)

3. A subretinal microchip that converts near-infrared light into electrical stimulation, acting as an electronic sensor to replace the photoreceptor cells

The entire working process, perhaps relying on these three parts of the system, only takes 6 steps.

1. The camera on the glasses captures the image

2. The image is converted into a near-infrared light pattern

3. The pattern is projected onto the chip in the eye

4. Each pixel of the chip responds to light → generating a microcurrent

5. The microcurrent stimulates the retinal neurons

6. The nerves transmit the signals to the brain → the brain "sees" the image

In summary, PRIMA doesn't repair the old retina; it simply installs a new photosensitive component in the eye.

80% can see, but it's not a "miracle"

The clinical medical technology company Science conducted this clinical trial at 17 hospitals in Europe.

All 38 subjects with dry AMD underwent implantation surgery. One year later, 80% of the patients had a significant improvement in vision (≥0.2 logMAR). Most people could read letters, numbers, and words again, and their peripheral vision was completely unaffected (using near-infrared light does not stimulate the remaining photoreceptor cells and does not interfere with the natural remaining vision).

The trial results define a clinically significant improvement as an improvement of at least 0.2 logMAR (i.e., the logarithm of the minimum angle of resolution; equivalent to an increase of ≥10 letters)

Although the 80% figure looks promising, this technology is far from perfect.

1. The "quality" of vision is not high

The PRIMA implant currently has only 378 pixels, with a theoretical resolution of approximately 20/417. Professor Frank Holz (the first author of the paper) admitted that this vision is black and white, not in color, and patients' reading is not fast or fluent but rather slow.

A patient is using the PRIMA system to read

2. Lack of a placebo control group

The biggest scientific limitation of this study is that it is a "single-group study," where all participants received the implant. It did not set up a placebo control group that received a "sham surgery".

Nature also reported on this breakthrough study, but in their review, they quoted the concerns of an anonymous researcher, "This improvement in vision may be partly attributed to intensive visual training and the excitement of patients having access to advanced medical equipment (i.e., the placebo effect)."

Without a control group taking a "sugar pill," there may be a placebo effect

3. No improvement in quality of life

A notable result is that although patients performed better on the eye chart, there was no significant overall improvement in the standardized questionnaire regarding "quality of life in daily life" (QoL).

This may mean that there is still a long way to go from "being able to read letters" to "truly improving the convenience of daily life."

4. Surgical risks

Since this is an invasive study, there are inevitably risks of varying degrees. The study reported a total of 26 serious adverse events (such as high intraocular pressure, macular holes, retinal detachment, etc.). The study emphasized that all these risks are related to the "implantation surgery" itself, rather than the PRIMA device.

Although there are some limitations, the progress of this study cannot be ignored. Other researchers have also conducted similar work on retinal implantation. Either the scope of application and the types of diseases are highly restricted, or they can only restore the ability to perceive light.

Like PRIMA, which enables patients to recognize letters, it can truly be said to be one of the most important advancements in the field of enabling the blind to regain their sight in decades.

Science Corporation is a clinical-stage medical technology company

Science Corporation, the company conducting the clinical research and the owner of this device, headquartered in San Francisco, submitted an application for marketing certification to European regulatory authorities in June this year.

Meanwhile, Daniel Palanker, a professor of ophthalmology at Stanford University and a co-author of the paper, said, "This is the first version of the chip, with relatively low resolution. The next-generation chip will have smaller pixels, higher resolution, and will be paired with more fashionable glasses."

AI glasses can help the blind gain vision and also benefit ordinary people

To be honest, every time I see news about "implanting a chip in the retina to enable the blind to see again," I'm both amazed and think... it seems so far away from us.

But the recently seen AI glasses have a completely different approach. They seem more practical, non-invasive, and accessible to the general public.

A popular video, "Losing" my eyes, I experienced a day of blindness with my self-made AI glasses... The open-source design drawing of the AI glasses in it

It doesn't "physically restore" the eyes in a hardcore way. Instead, it uses the power of AI to achieve a 24/7 "personal translator" - converting what the eyes see into real-time voice and telling you.

Although this isn't as groundbreaking as a brain-computer interface directly making images reappear, this concept really resonates with me: All our products should develop the accessibility mode as the default mode.