Neuroscientists and materials scientists have created contact lenses that enable infrared vision in both humans and mice by converting infrared light into visible light.
Because they’re transparent, users can see both infrared and visible light simultaneously, though infrared vision was enhanced when participants had their eyes closed.
To create the contact lenses, the team combined the nanoparticles with flexible, nontoxic polymers that are used in standard soft contact lenses.
In humans, the infrared contact lenses enabled participants to accurately detect flashing morse code-like signals and to perceive the direction of incoming infrared light.
“By converting red visible light into something like green visible light, this technology could make the invisible visible for color-blind people,” says Xue.
Through the conversion of infrared light into visible light, neuroscientists and materials scientists have developed contact lenses that allow for infrared vision in both humans and mice. The journal Cell describes contact lenses that allow the wearer to perceive multiple infrared wavelengths without the need for a power source, unlike infrared night vision goggles. Users can see both visible and infrared light at the same time because they are transparent, though closing participants’ eyes improved their infrared vision.
As a neuroscientist at the University of Science and Technology of China, senior author Tian Xue says, “Our research opens up the potential for noninvasive wearable devices to give people super-vision.”. “This material has a wide range of immediate applications. For instance, information could be transmitted using flickering infrared light in settings related to security, rescue, encryption, or anti-counterfeiting. “.
The nanoparticles used in contact lens technology absorb infrared light and transform it into wavelengths that are visible to human eyes (e.g. G. electromagnetic radiation between 400 and 700 nm. The nanoparticles specifically make it possible to detect “near-infrared light,” or infrared light that is slightly beyond what is currently visible to humans and falls between 800 and 1600 nm.
The team wanted to create a less invasive alternative, but they had already demonstrated that injecting these nanoparticles into the retina of mice allows them to see infrared.
The team used the nanoparticles in conjunction with nontoxic, flexible polymers found in regular soft contact lenses to create the contact lenses. They examined the contact lenses’ functionality in both humans and mice after demonstrating that they were nontoxic.
They discovered that mice wearing contact lenses showed signs of being able to see infrared wavelengths. Contact-wearing mice, for instance, preferred the dark box over the infrared-illuminated box when given the choice, while contact-less mice did not.
Additionally, the mice displayed physiological indicators of infrared vision: when exposed to infrared light, the pupils of contact-wearing mice contracted, and brain imaging showed that infrared light activated their visual processing centers.
Participants were able to perceive the direction of incoming infrared light and discern flashing signals that resembled morse code thanks to the infrared contact lenses.
Xue stated, “It’s very obvious: the subject can’t see anything without the contact lenses, but they can see the flickering of the infrared light clearly when they put them on.”.
Additionally, we discovered that the subject is even more capable of receiving this flickering information when they close their eyes because visible light interferes less with near-infrared light, which penetrates the eyelid more efficiently. “..”.
By designing the nanoparticles to color-code distinct infrared wavelengths, a further modification to the contact lenses enables users to distinguish between various infrared light spectra. As an illustration, infrared wavelengths of 980 nm were transformed into blue light, 808 nm into green light, and 1,532 nm into red light for example.
These colour-coding nanoparticles could be adapted to help color-blind individuals see wavelengths that they would not otherwise be able to detect, in addition to giving wearers the ability to see more detail in the infrared spectrum.
Xue says, “This technology could make the invisible visible for color-blind people by converting red visible light into something like green visible light.”.
The team used the same nanoparticle technology to create a wearable glass system that allowed participants to perceive higher-resolution infrared information because contact lenses have limited ability to capture fine details because of their close proximity to the retina, which causes the converted light particles to scatter.
The researchers are trying to improve the sensitivity of the nanoparticles so that they can detect lower levels of infrared light, as the contact lenses can currently only detect infrared radiation projected from an LED light source.
