Chinese Scientists Develop Infrared Contact Lenses Enabling Human Night Vision
TEHRAN (Tasnim) – Researchers in eastern China have created a new type of contact lens embedded with nanoparticles that allow humans to see infrared light, offering a compact alternative to traditional night vision technology.
Chinese scientists have developed infrared contact lenses that allow humans to see in the dark by converting invisible infrared light into visible light.
The breakthrough was achieved by researchers at the University of Science and Technology in Hefei, located in eastern China.
The team, led by Yuqian Ma, integrated 45-nanometer particles made of gold, sodium gadolinium fluoride, ytterbium, and erbium ions into conventional soft contact lenses.
According to findings published in the scientific journal Cell, the upconversion contact lenses (UCLs) are capable of converting infrared light with wavelengths ranging from 800 to 1,600 nanometers into visible light.
These nanoparticles increase the energy of long infrared waves and convert them into the three primary colors visible to the human eye.
One challenge the researchers encountered was image blurriness caused by light scattering through the nanoparticles.
This issue was partially resolved by supplementing the lenses with additional optical components.
Despite this, the new lenses are still significantly less powerful than conventional night-vision goggles, which amplify faint infrared signals.
Initial tests involved injecting nanoparticles into the retinas of mice.
The mice demonstrated the ability to navigate in darkness, suggesting they could perceive infrared light.
The new contact lenses, however, offer a more practical and non-invasive approach, requiring no injections.
In human trials, participants were able to distinguish patterns, letters, and flashing infrared signals in complete darkness.
Surprisingly, the lenses performed even better with eyes closed, as infrared light penetrated the eyelids without interference from ambient visible light.
Infrared perception is common in the animal kingdom.
Certain cold-blooded species—such as pit vipers, rattlesnakes, bullfrogs, piranhas, and mosquitoes—use it to detect heat radiation emitted by prey or their surroundings.
In contrast, warm-blooded animals, including humans, lack the receptors to perceive infrared light and are hindered by their own body heat.
The development of these lenses may mark a significant step forward in compact night vision technology, with potential applications in security, military, and rescue operations.
