Nanoparticles can enable superhuman night vision

Scientists have asserted their achievement in equipping mice with ‘night vision,’ enabling them to perceive infrared light while experiencing minimal adverse effects. This groundbreaking study holds the promise of propelling forward human infrared vision technologies, with possible implications spanning civilian encryption, security enhancements, and military maneuvers.

The Science behind it

The visual capabilities of humans and other mammals are confined to a specific range of light wavelengths termed as visible light, encompassing the hues of the rainbow. In contrast, infrared radiation, characterised by longer wavelengths, envelops our surroundings. Infrared light emission emanates from individuals, animals, and objects due to the release of heat. Additionally, objects have the capacity to reflect infrared light.

Electromagnetic waves, whether shorter or longer than visible light, carry a wealth of information within them. Gang Han, affiliated with the University of Massachusetts Medical School in the US, has elaborated, “As light enters the eye and reaches the retina, specialised cells known as rods and cones, or photoreceptor cells, absorb photons bearing visible light wavelengths. Subsequently, they transmit corresponding electric signals to the brain.”

Thus, scientists have created nanoparticles that can anchor tightly to photoreceptor cells and act as tiny infrared light transducers. When infrared light hits the retina, the nanoparticles capture the longer infrared wavelengths and emit shorter wavelengths within the visible light range. The nearby rod or cone then absorbs the shorter wavelength and sends a normal signal to the brain, as if visible light had hit the retina. The researchers tested the nanoparticles in mice, which, like humans, cannot see infrared naturally.

Its recent findings

As detailed in the journal Cell, the study’s outcomes revealed that a solitary injection of nanoparticles into the mice’s eyes granted them the ability to perceive infrared light for a duration of up to 10 weeks, accompanied by negligible adverse effects. This bestowed capability enabled the mice to discern infrared light both during daylight hours and with a sufficient level of precision to differentiate between distinct shapes.

Noteworthy indicators of the mice’s inadvertent perception of infrared light were evident among those that received the injections, including the constriction of their pupils. Conversely, mice subjected solely to the buffer solution exhibited no response to infrared light.

To evaluate the mice’s comprehension of infrared light, the researchers orchestrated a series of maze-based tasks that demonstrated the mice’s capacity to discern infrared light alongside visible light, even in daylight settings. While instances of side effects stemming from the injections, such as temporarily cloudy corneas, were infrequent, they resolved within a span of fewer than seven days.

So, will it work on humans? The scientists posit that the integration of these bio-responsive nanoparticles holds greater appeal for prospective applications of infrared technology in civilian encryption, security systems, and military maneuvers.