A Bionic Eye That Restores Sight

By bridging the gap between eye and brain, a new device has the capacity to help the blind regain their vision.
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Scientifically speaking, eyes are not the windows to the soul; they’re the windows to the brain. When you gaze into your lover’s peepers, what you’re actually seeing is the retina, an extension of brain tissue that lines the back of the eyes like wallpaper. This paper-thin strip of cells is what makes the miracle of sight possible. At this very moment, your retina is performing a kind of sensory alchemy, taking in rays of light and seamlessly transforming them into the language of the brain. And voila: vision.

What happens when this key conversion doesn’t take place? Lisa Kulik found out the answer in 1981, when she went in for a routine eye exam. Kulik had been having a little trouble seeing at night—nothing she was too concerned about. Then her eye doctor found dark spots on her retina.

Kulik had retinitis pigmentosa, a degenerative eye disease that affects 1 in every 4,000 Americans, according to the National Eye Institute. In retinitis pigmentosa, almost all of the eye’s circuitry remains intact—all but the crucial, light-absorbing cells of the retina. These slowly begin dying off, like stars winking out into the night. Without them, visual signals never make it to the brain.

Over the next 15 years, Kulik’s vision gradually deteriorated. She had to give up her job as a veterinarian’s assistant, forfeit her driver’s license, and finally, retire completely. Yet even after her world went fully dark, Kulik, now 54, remained hopeful. “When they diagnosed me, they told me there was no cure for it,” she says now. “That didn’t stop me. I knew someday, something was going to come along.”

In 2012, something did. Kulik’s husband was scanning news on his smartphone and came across something that sounded too good to be true: a report describing a medical device that promised to restore sight to those with Kulik’s disease. It was called the Argus II. He found the phone number for the company that was developing the device, called Second Sight.

Kulik called the number the next day, and was told that she would receive a call back when the Argus II gained FDA approval. “It was the first light of hope that something could help,” she says.

*  *  *

For centuries, scientists have marveled at the eye’s seemingly inexplicable complexity. Charles Darwin wrote in The Origin of Species: “To suppose that the eye with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest degree.” (Still, he went on to postulate just such an explanation: that a very simple eye first evolved and, through natural selection, progressed in gradations.)

The Argus II works not by seeking to replicate that complexity, but by tapping into the eye’s natural abilities. It bridges the gap between visual signal and brain—or, as Mark Humayun, the Argus’ creator and an opthamologist at the University of Southern California’s Keck School of Medicine, puts it: “The software speaks in the biological language.” The device relies on a small video camera affixed to a pair of sunglasses, which sends visual data to an electrode-covered microchip implanted at the back of the eye. The electrodes stand in for the damaged retinal cells, transmitting electrical signals straight to the optic nerve. The user receives the information in the form of a 60-pixel, black-and-white image.

Dr. Mark Humayun holds the Argus II
(Keck School of Medicine)

Humayun likes to compare the Argus II to VISOR, a fictional device in Star Trek: Next Generation worn by Geordi La Forge that similarly scans the electromagnetic spectrum and sends signals to the optic nerve. In fact, Humayun had come up with the idea for the Argus 10 years before the show aired, motivated by watching his grandmother lose her vision due to complications related to diabetes. “There wasn’t anything that could be done,” he says. “It made me reconsider my path in medicine.”

At the time, his design sounded far-fetched. The closest analog was the cochlear implant, which similarly converts sound into electrical impulses that the brain can understand. But Humayun’s undertaking had its own challenges. First, complexity: the ear has 30,000 hair cells, whereas the eye has 1 million ganglion cells, which translate light into pixels. Secondly, it would require implanting an electronic device into the most delicate part of the eye, the retina, where it would be subject to dislodging during the rapid eye movement part of sleep.

Twenty years and $200 million from private and public investors later, the Argus II became the first FDA-approved visual prosthesis available for commercial implant in February of last year. Nearly 80 people have had it implanted worldwide.

In early 2013, Kulik got a call back from Second Sight. She would be the third commercial patient in the U.S., and the first on the West Coast.

*  *  *

Last July, Kulik flew from Arizona down to USC for a series of eye tests. In the end, Kulik was chosen not only because she fit the requirements—her blindness had to be severe enough that she could benefit from the device—but also because of her optimism and dedication to learning how to use the Argus II, said Lisa Olmos de Koo, the eye surgeon at USC who performed the procedure.

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Rachel E. Gross is a writer based in Washington, D.C. Her work has appeared in Wired, New Scientist, and The New York Times.

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