Hand gestures captured on infrared imager device. (Image by Maximillian cabinet on Shutterstock)
Infrared Lenses Now Allow You To See In Complete Darkness Without Night Vision Devices
In a nutshell
- Scientists created transparent contact lenses that convert invisible infrared light into visible colors, allowing humans to see heat signatures and infrared patterns
- Human trials with 15 participants showed people could detect infrared signals, decode messages, and even see full-color infrared images that appear blank to the naked eye
- While the technology works safely for short-term use, it currently can’t produce sharp detailed images and requires artificial infrared light sources to be most effective
HEFEI, China — Scientists have solved two major limitations of human vision in one breakthrough: our inability to see in darkness and our blindness to infrared light. Newly developed contact lenses convert invisible infrared radiation into visible colors, effectively giving wearers both enhanced night vision and access to an entirely new color spectrum.
Published in the journal Cell, the study describes how researchers created these soft, transparent contact lenses embedded with microscopic particles that convert infrared radiation into visible light. Unlike traditional night-vision goggles that produces grainy green images, these lenses create sharp, colorful visuals that work seamlessly alongside normal eyesight in any lighting condition.
This development addresses a basic limitation of human vision. Although more than half of the solar energy reaching Earth exists in the infrared spectrum, our eyes are blind to it. The new lenses help bridge that sensory gap, converting previously invisible signals into visual cues that the human eye can detect.
How Do These Infrared Contact Lenses Work?
The lenses contain what’s known as upconversion nanoparticles—tiny components that absorb low-energy infrared light and emit higher-energy visible light. Embedding these particles into soft contact lens material posed a challenge: earlier attempts made the lenses cloudy or uncomfortable.
The breakthrough came when the research team, led by scientists from the University of Science and Technology of China and the University of Massachusetts Medical School, modified the nanoparticles to eliminate oily residues and carefully matched the way light bends through the lens material. The result was a contact lens with more than 90% transparency, even with nanoparticle concentrations as high as 7% by weight.
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Can Humans Actually See Infrared With These Lenses?
Tests on laboratory mice confirmed that the lenses enabled animals to distinguish between patterns made with infrared light. Remarkably, when the mice’s eyes were closed, they could still detect IR patterns through their eyelids—a feat not possible with visible light. This is because infrared light penetrates tissue more effectively than visible wavelengths.
“It’s totally clear cut: without the contact lenses, the subject cannot see anything, but when they put them on, they can clearly see the flickering of the infrared light,” says senior author Tian Xue, a neuroscientist at the University of Science and Technology of China, in a statement. “We also found that when the subject closes their eyes, they’re even better able to receive this flickering information, because near-infrared light penetrates the eyelid more effectively than visible light, so there is less interference from visible light.”
In human trials, 15 healthy participants aged 18 to 40 were divided into groups to test various capabilities. They successfully identified infrared light sources, distinguished between different IR wavelengths, and decoded simple messages sent through infrared pulses—demonstrating that humans could perceive and interpret these previously invisible signals using the lenses.
The lenses worked in both dark and well-lit environments, showing potential for use in a range of real-world conditions. “Our research opens up the potential for non-invasive wearable devices to give people super-vision,” says Xue.
Full-Color Infrared Vision May Be Possible
One of the most striking features of the study was the development of trichromatic versions of the lenses, which enable full-color infrared vision. These enhanced lenses use a mix of special nanoparticles that emit red, green, or blue light depending on the specific IR wavelength detected.
“By converting red visible light into something like green visible light, this technology could make the invisible visible for color blind people,” notes Xue.
In controlled experiments, participants wearing the color-enabled lenses matched invisible infrared patterns to specific colors. They were able to view text and shapes made from IR-reflective materials that appeared blank to the naked eye but became vividly colored when viewed through the lenses.
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What Are The Limits—and What’s Next?
While the lenses allow users to perceive infrared light and basic patterns, they currently cannot provide detailed image resolution due to the scattering of light during conversion. To address this, researchers developed a wearable eyeglass system that works in tandem with the lenses, improving clarity and enabling users to perceive spatial detail more accurately.
Detecting low-level, naturally occurring IR light—such as ambient thermal radiation—remains a challenge. Most tests required IR light sources like LEDs or lasers. Additionally, all human participants in the study were of East Asian ancestry, so broader population studies are needed.
Short-term safety tests revealed no major side effects, though minor irritation was noted with extended wear, similar to standard contact lenses.
If further developed, this technology could transform fields ranging from medicine to security. Surgeons could visualize blood flow in new ways. First responders might detect people through smoke or darkness. And wearable IR vision could assist with navigation in low-visibility conditions, from fog to disaster zones.
“There are many potential applications right away for this material. For example, flickering infrared light could be used to transmit information in security, rescue, encryption or anti-counterfeiting settings,” says Xue.
For the first time, researchers have demonstrated a safe, wearable device that gives humans access to a spectrum of light that has remained invisible for our entire evolutionary history. While still an early-stage technology, these contact lenses mark a significant step toward making infrared vision part of everyday life.
Paper Summary
Methodology
Researchers developed contact lenses by embedding upconversion nanoparticles (UCNPs) into soft polymer materials. They tested multiple polymer types to find optimal transparency while maintaining high nanoparticle concentrations. The team first conducted safety and effectiveness tests on laboratory mice, using various behavioral experiments to confirm the animals could detect and respond to infrared light. Human trials involved 15 healthy volunteers aged 18-40 with normal vision, divided into groups of 5 for different experiments testing visual sensitivity, pattern recognition, and color discrimination using infrared light.
Results
Mice wearing the contact lenses successfully detected infrared light patterns and made behavioral decisions based on infrared stimuli. Human participants could identify infrared light sources, distinguish between different infrared frequencies, decode temporal patterns (like Morse code), and recognize spatial patterns. Advanced trichromatic lenses enabled full-color infrared vision, allowing humans to perform color-matching experiments with invisible infrared light. The lenses maintained over 90% transparency while containing 7% nanoparticles by weight, worked in both dark and ambient light conditions, and didn’t interfere with normal vision.
Limitations
The contact lenses cannot produce sharp, detailed images due to light scattering during the conversion process from infrared to visible light. Detecting natural infrared radiation without artificial illumination remains challenging. The study’s human participants were all of East Asian ancestry, limiting generalizability. Extended continuous wear showed some minor irritation similar to regular contact lenses. Fine image perception requires additional wearable eyeglass systems to achieve optimal spatial resolution.
Funding and Disclosures
This research was funded by multiple Chinese government agencies including the Science and Technology Innovation 2030 Major Program, National Key Research and Development Program of China, Natural Science Foundation, and various provincial foundations. Additional support came from the New Cornerstone Science Foundation, Human Frontier Science Program, and Feng Foundation of Biomedical Research. The authors declared no competing interests.
Publication Information
Ma, Y., Chen, Y., Wang, S., et al. “Near-infrared spatiotemporal color vision in humans enabled by upconversion contact lenses,” published in Cell, 2025. DOI: 10.1016/j.cell.2025.04.019. The study was published online on May 22, 2025.
