Infrared vision is about to become democratic. What until yesterday required thousands of euros of equipment, can now be obtained with two transparent contact lenses. Professor Tian Xue and his team have solved one of the most complex problems in photonics: how to convert infrared light into visible light without using electrical energy.
The result? Lenses that work as a simultaneous translator between the visible and invisible worlds. And if you think it sounds too good to be true, tests on mice have already yielded surprising results. The study is published in Cell, but I'll explain it to you here too.
How the magic of nanoparticles works
The secret of these lenses lies in tiny nanoparticles that would make any magician envious. We are not talking about alien technology, but pure physics applied in an ingenious way. These microscopic particles are capable of capturing infrared photons (those that our eyes do not see) and combining them together to create visible photons. It's like taking two one cent coins and magically transforming them into a one euro coin.: more energy, more utility.
The nanoparticles used by the team of theUniversity of Science and Technology of China They work through a process called “upconversion.” In simple terms, they collect low-energy light (infrared) and release it as high-energy light (the kind we see). All this without the need for batteries, wires, or electrical connections. The energy source is the infrared light in the environment itself.
Infrared vision with closed eyes
Here's the part that really looks like incredible: These lenses work even when your eyes are closed. It's not a typo: infrared light can penetrate the eyelids much better than normal visible light, allowing you to perceive the light signals converted by the lenses even with your eyes closed.
During testing, subjects could distinguish the flashing infrared LEDs more clearly when they kept their eyes closed rather than open. The reason is simple: less interference from surrounding visible light. It's like having a phone conversation in a quiet room instead of in the middle of traffic.
From mice to humans
The researchers first tested miniaturized versions of the lenses on mice, with startling results. The animals equipped with infrared-vision lenses exhibited completely different behaviors when faced with choices that required them to distinguish between environments illuminated only by infrared light.
The “enhanced” mice always chose the dark environment over the one illuminated only with infrared light., demonstrating that they could perceive the difference. Their colleagues without lenses, however, could not distinguish between the two environments. A damning proof that the system really works.
Image: Yuqian Ma, Yunuo Chen.
The Future of Infrared Vision
Currently, the lenses only allow you to distinguish very intense infrared sources, such as specific LEDs. Don't expect to see human silhouettes like in action movies just yet. But according to what was published in the journal Cell, the team is already working to improve sensitivity and resolution.
Future applications could range from nighttime safety to medicine to assisting the visually impaired. Xue also sees potential uses for aiding the colorblind, by converting one part of the visible spectrum into another to allow color recognition.
There’s still a long way to go to democratize infrared vision, but these first steps show that the future could be more colorful (and warmer) than we imagine. And it’s all thanks to two small lenses that could change the way we see the world forever.
