A team of researchers at the University of Science and Technology of China (USTC) has developed soft contact lenses that use upconversion nanoparticles to convert infrared light into visible light, allowing humans to see in infrared. Unlike night-vision goggles, which only see infrared light in green, these contacts can see it in red, blue, and green wavelengths.
The lenses work by attracting water molecules, making them hydrophilic, and converting near-infrared (NIR) light into shorter red, blue, and green wavelengths that fall within the visible light range. This technology is made possible by upconversion nanoparticles, which were developed for this study.
Researchers tested these contact lenses on mice and found that hours of wear had no effect on their ability to see in infrared, suggesting that it did not interfere with their visible light sensitivity. Human subjects also showed no decrease in sensitivity to visible light while wearing the contacts.
One notable feature of these lenses is that they allow users to see in infrared even with eyes closed. The researchers plan to continue improving this technology, which could provide military and police operations an edge by detecting anti-counterfeit marks and enhancing night vision capabilities.
Source: https://www.popularmechanics.com/science/health/a64889270/infrared-contact-lenses