A team of researchers in China has developed infrared contact lenses that make it possible at night. With the help of nanoparticles, the lenses make visible for the human eye the wavelengths of invisible light, reports Deutsche Welle.
The light is made up of individual particles that propagate in waves. The wavelength determines the color and energy of light.
The human eye can only perceive a small part of this spectrum, approximately the range between 400 and 700 nanometers (NM).
For this reason, we people are not able to see the infrared range, with its larger wavelengths, from 750 nanometers to 1 millimeter.
Therefore, to see the infrared light, I needed nightmare glasses, some relatively bulky, or at night views with their own energy source. But that until now.
China infrared contact lenses
Researchers at the University of Science and Technology in Hephei, city in eastern China have now developed a contact lens that converts infrared light into visible light, thus allowing people to see in the dark.
Dr. Yuqian Ma and his team combined conventional soft contact lenses with 45 nanometers composed of gold, sodium gadoliniu fluoride, yarbiu and Erbiu.
These contact lenses with ascending conversion (UCL) transform infrared light with wavelengths between 800 and 1600 Nm (invisible spectrum for humans) in visible light, wrote the team of researchers in the scientific magazine Cell.
Nanoparticles enrich the long waves of infrared light with energy. In this way, they turn infrared light into three primary colors, making them visible to the human eye.
A disadvantage is that the resulting images are very unclear because the nanoparticles in the lenses spread the light, which the team of researchers has managed to partially compensate by adding additional lenses.
But nevertheless, infrared contact lenses are by no means as powerful as the eyeglasses at night, which amplify the weak infrared signals, making them visible.
An even better view with eyes closed
The lenses were tested on both animals and humans. The researchers first injected nanoparticles into the retina of mice, and their behavior showed that they can see in the dark.
Newly developed contact lenses are much more practical, because they are non-invasive-that is, without injections in our retina.
During the tests, they were able to recognize intermittent infrared models, letters and signals in the dark.
And the infrared lenses work even better with the eyes closed, because the infrared light can easily penetrate the eyelids, and the generation of images is not disturbed by the normal visible light.
The big question about benefits
As fascinating is the innovation of Chinese researchers, it remains to be seen how it could be used in everyday life.
According to the team, the lenses could be used in surgical procedures, in the field of encryption or cryptography, or to protect against counterfeits – and this is due to the fact that infrared light is visible invisible safety elements or ink on documents, for example.
The lenses could also be used to save people under low visibility conditions, because they make visible the objects that emit heat. But this is called into question by some criticisms, because at night vision devices are much easier to use and are also much stronger.
