Neuralink's 'breakthrough device' clearance from FDA does not mean it has cured blindness
Neuralink, the Elon Musk-owned brain-computer interface company, on Tuesday received "breakthrough device" clearance from the FDA. But this does not mean the outfit has developed a cure for blindness, no matter what Musk might say.
The breakthrough devices program at the FDA is a voluntary program that developers can apply to that, if granted, "offers manufacturers an opportunity to interact with FDA experts through several different program options to efficiently address topics as they arise during the premarket review phase." The designation also lines up recipients for priority FDA review.
In 2023, 145 medical devices were given this same breakthrough designation, and almost 1,000 have been authorized since the program was rolled out in 2015.
Neuralink's Blindsight, the latest recipient, is a new iteration of a technology that has been used for decades to experimentally restore very limited vision to certain blind people. A microelectrode array is embedded in the visual cortex and stimulates the neurons located there in patterns derived from a camera. In a way, it really is that simple to produce visual phenomena in people who may never have seen before.
Musk lost no time in asserting that Blindsight will "enable even those who have lost both eyes and their optic nerve to see. … [I]t will even enable those who have been blind from birth to see for the first time."
But it is extremely premature to say that such a device could enable blind people to see. The issue historically has been the low density of electrodes on the array, which is on the order of dozens, meaning what is "seen" is really more like a few stars winking on and off with no discernible pattern, because the parts of the cortex pierced and stimulated are essentially random.
Neuralink's advance — which is very welcome in this field — is increasing that density. But the approach suffers from the same fundamental drawbacks.
Musk is implying that the device would plug in and grant sight. That is not possible. Even among those who have only recently lost their sight to trauma or disease -- which are by far the most common causes -- meaning the visual cortex has been trained since birth to function normally, sight would not be "like Atari graphics," as Musk suggests. While there is a surprising and promising level of plasticity in adapting to systems like this, it is a difficult and disorienting process.
Furthermore, people who have been blind from birth will not have developed the biological capacity for seeing through their eyes, meaning that despite the visual cortex's cellular layout being optimized for vision tasks, the pathways that create the concept of vision sighted people understand will not exist. It is misleading for Musk to suggest otherwise, though I suspect the blind and low-vision community is accustomed to sighted people making this kind of mistake.
This is not all to say that Neuralink's Blindsight is bad or won't work — the company appears to have created a genuinely better microelectrode array, and possibly the means to implant it more efficiently and with lower risk of rejection or brain damage.
While it's irresponsible for Musk to make the same bombastic "Geordi La Forge" promises that others have made these last few decades in this area of research, the device and methods he has funded will almost certainly contribute to a future where electronic implant-based treatments for blindness become realistic.
If Musk's companies ever responded to press inquiries (Neuralink did not immediately reply to a request for comment) or discussed and published their research more openly, we would have a more open discussion among domain experts about the merits and challenges of this approach.
As it is, we may hope that, now that the FDA has given Neuralink permission to take its shot at justifying the device's use in humans, the company will operate more in the open.