Scientists say they successfully gave mice "night vision" so they can see infrared light with minimal side effects.
Research could lead to advances in human infrared vision technologies, including potential applications in civilian encryption and security and military deployments, scientists said.
According to the study published in the journal Cell, a single injection of nanoparticles in the eyes of the mice gave up to 10 weeks of infrared vision with minimal side effects, so they could even see infrared light during the day and with sufficient specificity to switch between different forms to distinguish.
Humans and other mammals are limited to seeing a wavelength range of visible light that includes the wavelengths of the rainbow.
Infrared radiation a longer wavelength is all around us. People, animals and objects emit infrared light when they give off heat, and objects can also reflect infrared light.
"The visible light that can be perceived by human natural vision occupies only a very small portion of the electromagnetic spectrum," he told Tian Xue of the University of Science and Technology of China.
"Electromagnetic waves that are longer or shorter than visible light contain much information," Xue said.
"When light enters the eye and the retina, rods, and eyes hit cone or photoreceptor cells, they absorb the visible wavelengths of light and send appropriate electrical signals to the brain," said Gang Han of the University of Massachusetts Medical School in the USA.
"Because infrared wavelengths are too long." Can not be detected by photoreceptors, "said Hans.
Scientists made nanoparticles that firmly attach to photoreceptor cells and act as tiny infrared light transducers.
When infrared light strikes the retina, the nanoparticles trap the longer infrared wavelengths and emit shorter wavelengths in the visible light range.
The nearby rod or cone then absorbs the shorter wavelength and sends a normal signal to the brain as if it had the visible light met the retina.
Researchers screened the nanoparticles on mice that, like humans, can not see infrared naturally.
Mice receiving injections showed unconscious physical signs of detecting infrared light, such as mice, which only the buffer solution had been injected did not open Infrared light reacted.
To test whether the mice can understand the infrared light, the researchers performed a series of labyrinth tasks to show that the mice can see infrared in daylight conditions simultaneously with visible light.
In rare cases, side effects from injections such as cloudy corneas appeared, but these disappeared within less than a week.
"We believe this technology will also work for the human eye, not only for the generation of supervision, but also for therapeutic solutions to red color deficits in the red color," said Xue.
Today's infrared technology relies on detectors and cameras that often have a limited number of sensors, ambient light, and power sources.
Researchers believe that biopolymerized nanoparticles are more desirable for potential infrared applications in civilian encryption, security, and military operations.