Scientists successfully develop dark-vision contact lenses, enabling sight in darkness, irrespective of eyelid position.
Researchers in China have developed a groundbreaking technology that enables the human eye to perceive infrared light, both in darkness and, surprisingly, with closed eyes. This technological marvel is achieved through the use of upconverting nanoparticles integrated into soft contact lenses.
The phenomenon of "seeing with closed eyes" comes about due to the superior penetration of near-infrared light through the eyelid compared to visible light. Remarkably, this futuristic enhancement does not require a power source.
The science behind this innovation relies on the upconverting nanoparticles - a fascinating physics concept that pushes the boundaries of human vision. Typically, the human eye can detect electromagnetic radiation ranging from around 400 to 700 nanometers, encompassing visible light from violet to red. Beyond this range, such as ultraviolet or infrared light, remains invisible to us because our photoreceptors do not respond to it.
However, these engineered contact lenses alter the rules. The upconverting nanoparticles absorb multiple low-energy infrared photons, each of which would be invisible on its own, and combine their energy to emit a single, higher-energy photon in the visible spectrum. These particles absorbglimmers of low-energy infrared light (800-1,600 nm) and emit single bursts of visible light (400-700 nm), directly onto the cornea.
This process shares similarities with night vision goggles, though with an important twist. Traditional night vision goggles, initially developed during World War II, typically use an image intensifier tube. This technology requires electricity, bulky hardware, and a lens system to function. In contrast, the new lens is more efficient and doesn't require external power.
Lead researcher Tian Xue, a neuroscientist at the University of Science and Technology of China, commented, "Our research opens up the potential for non-invasive wearable devices to give people super-vision." He sees numerous potential applications for this material, such as using flickering infrared light for information transmission in security, rescue, encryption, or anti-counterfeiting settings.
The team previously demonstrated this concept in mice by injecting the particles directly into their eyes. This was a powerful proof of concept but not exactly a comfortable upgrade for humans. The new lenses sidestep the need for syringes.
The researchers first tested the lenses in mice, whose pupils contracted in response to infrared stimuli, and brain scans showed that visual areas lit up as they would with normal light. The mice were placed in a "light or no light" maze and preferred hiding in dark boxes, as expected. However, when infrared light lit one of the boxes, only lens-wearing mice avoided it - evidence that they could now see wavelengths beyond their natural reach.
The researchers then moved on to human trials. Participants wearing the lenses were able to detect Morse-code-like infrared flashes and determine their direction. Interestingly, the lenses also worked with closed eyes - a seemingly supernatural ability that may make for challenging sleeping conditions.
The researchers also aimed to help users discriminate between different wavelengths of infrared light by color. The lenses were designed to create different colors based on the specific infrared wavelengths. For instance, 980 nm infrared appeared blue, 808 nm turned red, and 1532 nm showed up as green. This approach could potentially aid users in reading invisible codes or assisting people with color blindness in perceiving a wider spectrum of colors.
While there are limits to the lenses' capabilities, they represent an exciting leap forward in wearable technology and hold great potential for vision enhancement. However, scientists must still solve several engineering challenges, such as enhancing spatial resolution, boosting sensitivity to lower light levels, and ensuring the long-term safety of the nanomaterials, to realize the full potential of this breakthrough technology. The study was published in Cell.
- Remarkably, the new technology in the form of soft contact lenses, developed by researchers in China, allows humans to perceive infrared light, even with closed eyes, thanks to upconverting nanoparticles.
- The science behind this innovation lies in the upconverting nanoparticles, a physics concept that pushes the boundaries of human vision, as they can turn low-energy infrared photons into visible light.
- Tian Xue, the lead researcher, remarks that this innovation opens up the potential for non-invasive wearable devices to give people super-vision, with possible applications in security, rescue, and anti-counterfeiting settings.
- These lenses are more efficient than traditional night vision goggles, which require electricity, bulky hardware, and a lens system to function, making them a stepping stone into the future of tech and science.
- Genetics research may be expanded with the help of these lenses, as they could potentially aid people with color blindness in perceiving a wider spectrum of colors based on different infrared wavelengths.
- While the lenses represent an exciting leap forward in wearable technology, scientists must still tackle engineering challenges to ensure their long-term safety and optimize their capabilities, such as enhancing spatial resolution, boosting sensitivity to lower light levels, and improving wavelength discrimination.
