Innovative eye implant brings hope to blind
Baku, October 8, AZERTAC
After spending more than 30 years navigating life in relative darkness, a visually impaired man, surnamed Qiu, believed the prospect of regaining some sight was gone forever, according to China Daily.
However, Qiu is now able to recognize and write numerals, Chinese and English characters, grasp items with his hands, and avoid obstacles when walking. Thanks to the latest developments in brain-computer interface technology, some semblance of sight is being brought to people with visual impairments.
Qiu regained his ability to "see" by wearing a pair of specially-made glasses. Cameras on the glasses capture real-time images of the outside world and complete photoelectric conversion, with signals transmitted to an external control encoder.
The encoder decodes and re-encodes the signals, and drives the chip embedded in the scleral interlayer via wireless transmission. The chip emits electrical signals to stimulate the ocular nerves, which in turn send electric impulses to the brain's visual cortex to generate visual perception.
"Upon putting on the glasses, the patient immediately feels photoelectric stimulation and perceives light spots. With three training sessions per week, between the first and third weeks, the patient is able to recognize and write down numbers, letters and Chinese characters, grasp objects accurately, and walk independently along visual markers.
"However, prolonged systematic training is required for the patient to read texts accurately and distinguish finer-detailed objects," said Xiao Xuan, vice-president of Renmin Hospital of Wuhan University in Hubei province.
The hospital performed the chip implantation surgery on Qiu in July.
"Artificial vision is similar to a baby learning to understand the world all over again. A new set of recognition-related skills needs to be cultivated. Patients need repeated training to build connections between electrical stimulation signals and real-world objects," she said.
After a month of rest following the surgery, Qiu began his training at the hospital. Xiao said Qiu's improvement exceeded expectations, adding that the duration for adaptation is about six months in hospital before a patient can begin home training.
"The long-term goal is not to merely chase clinical vision measurements. Instead, it is to enable patients to live independently such as traveling on their own, avoiding obstacles, and recognizing banknotes, thereby reducing the burden of family care," she added.
What makes this surgery unique is that a chip no larger than half a small fingernail was implanted into the outer wall of the eyeball, the sclera. The chip did not penetrate the eyeball, involved no connecting wires between the inside and outside of the eye, and required no auxiliary devices such as external magnetic snaps. The high-resolution chip can greatly improve the accuracy of object recognition. As a semi-invasive solution, it causes less damage to the human body compared with similar surgical procedures. "Even though the chip is not placed right against the retina, its electrical signals can still stimulate nearby nerve pathways to transmit signals and produce visual perception. This solution also supports broader surgical indications and offers greater safety," she said.
China has roughly 50 million patients with fundus diseases — a group of conditions that affect the interior surface of the eye — among whom 24 million suffer from blindness caused by retinal nerve damage.
According to Xiao, this BCI technology applies to seven types of blindness caused by nerve damage, covering approximately 80 percent of patients with irreversible blindness. The conditions include retinitis pigmentosa, advanced age-related macular degeneration, central retinal artery occlusion, ischemic optic neuropathy, advanced glaucoma, late-stage retinal detachment, and diabetic retinopathy.
According to Xiao, patients with complete destruction of the eyeball and optic nerve are not eligible for this treatment, though other surgical approaches are available for them.
"Natural vision works when photoreceptors capture light, and multiple layers of nerve cells pass signals step by step. This enables color recognition, depth perception and stereoscopic vision. Artificial vision creates phosphenes by electrically stimulating nerves with electrodes, producing pixel-like images. It will be very hard to fully replicate normal natural vision in the short term. Though theoretically possible in the long run, this faces huge challenges in technical pathways," she said.
Currently the biggest challenges include reconstructing color vision, which is extremely difficult to achieve, and decoding the precise signal mapping between retinal nerves, the optic nerve and the brain's visual cortex. "Only by building an accurate and complete mapping model can we achieve high-fidelity imaging, stereoscopic vision and depth perception, greatly improving the quality of artificial vision," she added.
Looking ahead, with the rapid advancement of AI technology and precise analysis of the eye-brain mapping system, researchers are expected to build a complete external artificial vision system. It would communicate directly with the human visual center without relying on conventional tissues or organs. "Similar to plots in The Three-Body Problem, technology will turn science fiction into reality," she said.
Qiu has long worked as a blind massage therapist. For him, blindness made traveling risky. He once was almost struck by an electric motorbike on the street, so he hardly dared to go out alone.
"I am happy to be able to gradually regain visual perception," he said.
He mentioned that during the initial phase of electrical stimulation and device debugging, he experienced mild irritation in his eye, to which he quickly adapted.
Doctors said that such discomfort would gradually subside with consistent training and gradual adaptation. He looks forward to this technology making his life more convenient in the future.
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