Scientists have developed a new type of retinal implant that not only restored vision in blind mice but also gave them the ability to see infrared light—something even healthy eyes cannot detect.
The device, made from interwoven tellurium nanowires, represents a significant step forward in artificial vision technology and could eventually help millions of people worldwide living with blindness.
The research, published today in Science, demonstrates how the nanoprosthesis successfully restored reflexes and visual behaviors in genetically blind mice while extending their perception into the near-infrared spectrum. In tests with non-human primates, the implants proved safe and effective, with one sighted macaque gaining infrared sensitivity without losing normal vision.
Beyond Traditional Approaches
Current vision restoration technologies face substantial obstacles including electrical interference, short-term effectiveness, and the need for bulky external equipment. Most retinal prostheses require external power sources, cameras, and control modules that limit real-world applications.
The new tellurium-based device sidesteps these problems through an elegant design. The nanowires naturally convert light into electrical signals without requiring external power, functioning more like biological photoreceptors. “The long-term success of these technologies depends on developing cost-effective solutions and ensuring their availability to a broader range of patients,” notes Eduardo Fernández in a related perspective piece.
What makes this approach particularly compelling is the material choice. Tellurium, a silver-white semiconductor element, has unique properties that enable it to respond to both visible and infrared light. The researchers constructed the nanowires into an interlaced network that can be easily implanted in the subretinal space.
Impressive Performance Metrics
The device achieved remarkable technical specifications that set it apart from existing technologies. The tellurium nanowires generated photocurrent densities up to 30 amperes per square centimeter—the highest reported for any retinal prosthesis material. Equally important, the device responded to wavelengths from visible light all the way to 1550 nanometers in the near-infrared spectrum, far exceeding the range of previous approaches.
In blind mice, the implants triggered activity in both the optic nerve and visual cortex when exposed to light. The animals showed improved pupil responses and performed better on pattern recognition tests, eventually matching the performance of mice with normal vision. Crucially, these improvements occurred at light intensities nearly 80 times weaker than clinical safety thresholds.
Infrared Vision Opens New Possibilities
The ability to detect infrared light could prove especially valuable for vision restoration. Infrared provides better contrast in low-light conditions and could help patients navigate in darkness. Some animals, like certain snakes, naturally possess this capability and use it to assess their environment more accurately.
The research team tested this infrared sensitivity extensively. Blind mice with implants could locate LED lights and recognize geometric patterns using 940-nanometer infrared illumination—wavelengths completely invisible to normal mammalian eyes. In behavioral tests, these mice achieved correct response rates of approximately 67% when detecting infrared signals, compared to just 12% for normal mice.
Safety and Biocompatibility
Extensive testing revealed the implants to be well-tolerated by biological tissue. In mouse studies lasting up to 60 days, researchers found no significant differences in retinal cell numbers between implanted and non-implanted areas. While some initial immune cell activity was detected, this resolved within two weeks of implantation.
The primate studies provided additional confidence in the technology’s safety profile. A crab-eating macaque monitored for 112 days after implantation showed no signs of retinal damage, bleeding, or abnormal tissue changes. Importantly, the implant remained stable and maintained close contact with retinal tissue throughout the observation period.
Technical Innovation
What enables this broad spectral response lies in the nanowires’ engineered asymmetries. The researchers discovered that internal defects and external interface effects work together to generate robust electrical currents when light hits the material. Through quantum transport simulations, they showed how these asymmetries break the material’s natural symmetry and enable efficient light-to-electricity conversion across a wide wavelength range.
One particularly noteworthy finding not emphasized in initial reports involves the device’s temporal response characteristics. The implants successfully tracked flickering light at frequencies up to 12 Hz, with optimal responses around 4 Hz. This temporal resolution closely matched that of normal retinal function, suggesting the artificial system can integrate well with existing neural pathways.
Looking Ahead
While these results are encouraging, significant challenges remain before human trials can begin. The researchers acknowledge that the overall light sensitivity of their device remains much lower than natural photoreceptors. This means patients might need assistive technologies like specialized goggles to optimize performance.
The team also notes that visual cortex plasticity differs between species, and the extent to which human patients could adapt to restored vision remains unclear. Previous studies suggest that motion processing may be more robust than shape recognition after long-term visual deprivation.
Despite these challenges, the work represents a meaningful advance in artificial vision technology. By combining vision restoration with infrared sensitivity in a device that requires no external power, the researchers have created a platform that could eventually benefit the estimated 285 million people worldwide who are blind or visually impaired.
The successful demonstration in both rodent and primate models provides a foundation for future clinical development, potentially offering patients not just restored sight, but enhanced visual capabilities beyond normal human perception.
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