A Sino-U.S. joint research project has enhanced the vision of mice by using nanotechnology to make them see infrared light as well as visible light, which could lead to applications for humans to have an infrared vision in the future.
The mice were able to detect near-infrared light (NIR), as well as normal light, for about 10 weeks without any long-term side effects, the study published Thursday in the science journal Cell found. This tech worked with the structures that already exist in the eye to push vision beyond the realm of visible light.
Mice are already masters of lurking in the shadows, well out of sight of prying human eyes, but researchers in the USA and China just turned a few of them into serious superheroes.
The injected nanoparticles anchored themselves to photoreceptors within the eyes of the mice.
Humans and other mammals are limited to seeing a range of wavelengths of light called visible light, which includes the wavelengths of the rainbow. The mice proved able to see infrared even in daylight conditions, with regular light also crowding their retinas.
Neuroscientist Dr Jin Bao, a member of Prof Xue's lab, said: "In our experiment, nanoparticles absorbed infrared light around 980 nm (nanometres) in wavelength and converted it into light peaked at 535 nm, which made the infrared light appear as the colour green".
Seeing near infrared light directly would mean army personnel on unsafe missions would no longer need to wear cumbersome night vision goggles.
Anything that gives off heat-people, animals, objects-gives off infrared light. "So we believe this technology will also work in human eyes, not only for generating super vision but also for therapeutic solutions in human red color vision deficits".
When the light hits the retina, the rods, which are wrapped around the eye's natural photoreceptor cells, are able to absorb light at a much longer wavelength than our current vision can expect.
Both ultraviolet and infrared light falls outside of this range. Mice that were injected with the nanoparticles showed unconscious physical reactions to infrared light detection, while those that received only a buffer solution couldn't see the infrared light.
Sometimes, there were side effects in which cloudy corneas appeared, but disappeared within a week. Tests found no damage to the retina's structure, suggesting that the procedure is safe.
The researchers believe the bio-integrated nanoparticles are more desirable for potential infrared applications in civilian encryption, security and military operations.
In the future, the researchers plan to tweak their nanoparticles to better suit human eyes, which have more cones and rods than mice.
A recent scientific breakthrough made jointly by scientists in China and the United States will enable mammals to see in the dark, and also serve as the basis for fixing human beings color blindness.