Infrared-sensing Contacts Demonstrated in Humans

Night-vision goggles work much in the same way that these new lenses do, allowing humans to see infrared radiation, but are bulky and need a power source. They also operate solely on a green scale, while the UCLs offer richer, multicolored infrared images. These images from the study show visible and near-infrared stimuli shown to subjects. Note how reflectance #3 is black in visible light but perceptible as a purple T while wearing the contact lenses. Click image to enlarge. Humans can only perceive images within the very narrow range of visible light—between about 380nm to 750nm. While infrared goggles allow people to detect other wavelengths, such technology is limited to head-mounted eyewear—for now. In a new study published in the journal Cell, researchers based in China were able to successfully create and implement contact lenses that convert near-infrared (NIR) wavelengths into something detectable by humans.Called upconversion contact lenses (UCLs), they were originally tested on mice. The mice wearing the UCLs could recognize NIR temporal and spatial information, as evidenced by choosing a dark, “safe” box over one that was lit up with infrared light.1 Conversely, mice that did not wear the lens displayed no preference.1 The lenses made for human subjects had suitable optical properties, hydrophilicity, flexibility and biocompatibility, resulting in participants being able to discriminate NIR information—including temporal coding and spatial images. This was demonstrated through subjects’ ability to detect infrared flickering light from an LED, in which Morse code signals were perceived, as was a sense in which direction the signals were coming from.1 Performance of the UCL also improved in people when they closed their eyes; this is due to near-infrared light easily being able to penetrate eyelids, with visible light potentially interfering with image formation when eyes are open.1The trichromatic soft lens works by allowing wearers to delineate multiple spectra of NIR light—functioning as three primary colors—thus resulting in human NIR spatiotemporal color vision.2 The lens was created with nanoparticles made of rare earth materials ytterbium and erbium.1 However, nanoparticle integration into polymeric materials typically used for contact lenses can alter optical properties. To maintain lens transparency, polymeric materials were screened based on refractive index, with researchers developing a process that resulted in over 90% transparency across most wavelengths.2  Another complication of nanoparticle-based lenses like this is that  such particles scatter light, making images created by the lenses blurry.1 The researchers combatted this setback by also creating glasses with additional lenses that redirect the light.1Although more of a scientific feat than a practical implementation at the moment, possible use for these lenses may include the ability to read anti-counterfeit marks emitting infrared wavelengths undetectable to the naked eye or doctors performing near-infrared fluorescence surgery to detect and remove cancerous lesions.1Distilling their complex research, the authors wrote in their paper for Cell that “this work advances the development of trichromatic orthogonal particles for biological visual sensation and recognition.”2They add that, “overall, this concept-proving study confirms that human super-vision ability can be achieved by wearable nano-biomaterials and paves the way to numerous applications of human NIR spatiotemporal color vision.”2In an article for Scientific Reports, Yuqian Ma, one of the researchers, said, “Witnessing people wearing contact lenses and successfully seeing infrared flashes was undoubtedly an exhilarating moment.” Click here for the journal source. 1. Gibney E. These contact lenses give people infrared vision—even with their eyes shut. Springer Nature. www.nature.com/articles/d41586-025-01630-x. Published May 22, 2025.2. Ma Y, Chen Y, Wang S, et al. Near-infrared spatiotemporal color vision in humans enabled by upconversion contact lenses. Cell. 2025;188:1-14.