Eduardo Fernandez, director of neuroengineering at the University of Miguel Hernadez in Elche, Spain, has been working to return sight to as many of the 36 million visually impaired people worldwide, as possible. Now, a new breakthrough has granted one woman her sight for the first time in 16 years. This new discovery gives the blind vision, but it’s not perfect yet – let’s take a look.
The patient
Bernardeta Gómez lost her vision 16 years ago. She had toxic optic neuropathy, which destroyed the bundle of nerves that connects her eyes to her brain – she’s totally without sight, unable to even detect light. But after nearly two decades of blindness, she was given a six-month period during which she was able to detect very low-resolution images of the world, represented by white-yellow dots and shapes.
This was thanks to a modified pair of glasses, which were fitted with a tiny camera, connected to a computer that processes live video and turns it into electronic signals. A cable hanging from the ceiling then connected the system to a port embedded into a 100-electrode implant in the visual cortex of her brain.
Using this system, she could identify ceiling lights, basic shapes on paper, and even people. She also played a Pac-Man-like computer game, that was sent directly to her brain. Gómez’s first moment of sight came at the end of 2018. It marked the decades of research conducted by Eduardo Fernandez – whose approach bypasses the eyes and optic nerves altogether, and could potentially provide sight to 36 million blind people around the world.
The implant
If the general idea behind Fernandez’s project is relatively simple, the actual process is not. First, Fernandez and his team had to work out what kind of signal the human retina actually produces. He has a working relationship with a local hospital, which sometimes calls in the middle of the night when an organ donor has died.
Fernandez takes human retinas from people who are recently deceased, and hooks them up to electrodes, exposes them to light, and measures what hits the electrodes. His team also uses machine learning to help match the retina’s output to simple visual inputs, which helps them write software that will mimic the process automatically.
Then, Fernandez must take this signal and deliver it to the brain. In the implant built for Gómez, a cable connection runs to a neuro-implant known as a Utah array, which is smaller than the raised tip on a triple A battery. The implant is made up of 100 tiny electrode spikes, and looks like a bed of nails. Each electrode can deliver between one and four neurons. When it’s inserted, it pierces the surface of the brain.
Fernandez had to calibrate each electrode, one by one – sending increasingly strong currents until Gómez could see a phosphene. It took a month to get all 100 electrodes tapped in.
“The advantage to our approach is that the array’s electrodes protrude into the brain and sit close to the neurons,” Fernandez says. This means that the implant can produce sight with a low electrical current, which vastly reduces the risk of seizures.
This discovery gives the blind vision, but it still has one major problem: nobody knows how long the implant will last for. According to Fernandez, “The body’s immune system starts to break down the electrodes and surround them with scar tissue, which eventually weakens the signal,” Fernandez supposes the current setup could last two to three years, or maybe 10 before it fails. Fernandez hopes that some small changes could extend that to a few decades – a vital factor for an implant that requires brain surgery.
Still a way to go
This discovery gives the blind vision, but it still has some room for improvement. While Gómez was partially sighted for 6 months, nothing was exactly crystal clear. Furthermore, nobody knows how long this current implant will last before the body starts to break it down. With that being said, Fernandez’s work could potentially bring sight to 36 million blind people around the world (those who want it), which is groundbreaking. Let’s see where this new research goes, but it certainly looks promising.
