Innovative Contact Lenses Grant Humans Infrared Vision

Researchers have developed contact lenses that can convert infrared light into visible light, enabling night vision for humans.

The lenses are embedded with nanoparticles of gold and rare earth metals, allowing wearers to recognize patterns, letters, and flashing infrared signals in darkness.

Nanoparticles Enable Night Vision

Scientists at the University of Science and Technology in Hefei have engineered contact lenses that empower individuals to see in low-light conditions. These lenses have the ability to convert infrared light into visible light without the need for an external power source.

Yuqian Ma and his research team have integrated traditional soft contact lenses with 45-nanometer particles made up of gold, sodium gadolinium fluoride, ytterbium, and erbium ions. Known as upconversion contact lenses (UCL), these innovative lenses transform infrared light with wavelengths ranging from 800 to 1,600 nanometers into visible light.

Tests on Mice and Humans

Initially, the team conducted experiments on mice by injecting nanoparticles into their retinas. The animals exhibited the ability to see in the dark, validating the effectiveness of the technology. Unlike invasive procedures such as retinal injections, the newly developed contact lenses offer a more practical solution.

In human trials, participants were able to identify patterns, letters, and flashing infrared signals in dark environments. The lenses perform optimally with closed eyes, as infrared light can easily pass through the eyelids without interference from normal visible light.

Limitations Compared to Night Vision Goggles

Although the lenses enhance visibility in low-light conditions, the resulting images may appear blurred due to light scattering by the nanoparticles. To address this issue, the team has incorporated additional lenses. However, these contact lenses do not match the performance of night vision goggles, which amplify weak infrared signals.

Animals with Infrared Capability

While humans and warm-blooded animals typically lack the ability to see infrared light, certain species possess this capability. Cold-blooded reptiles, such as snakes, as well as specific fish, amphibians, and insects, utilize infrared vision for hunting and orientation in darkness.

Possible Applications

The developers envision various applications for the contact lenses, including their use in surgical procedures, cryptography, and counterfeit protection. Infrared light can reveal hidden features or inks on documents, making them useful for security purposes.

Additionally, the lenses could aid in search and rescue operations under low-visibility conditions by making heat-emitting objects visible. However, some critics question the practicality of this application, favoring the use of traditional night vision devices for enhanced performance.