Scientists have developed contact lenses that allow people to see infrared light. The lenses may also help people with color blindness.
The lenses are transparent, and when you put them in, you can see all the normal colors and infrared light, scientists write in the scientific journal Cell Journal.
It’s a kind of superhuman vision. Normally, people can only perceive light with certain wavelengths, namely between 380 and 780 nanometers. That part of the electromagnetic spectrum is called visible light. As a result, we see a wide range of colors. Red, for example, has longer wavelengths than blue.
The wavelengths of infrared light are longer, namely from 780 to 100,000 nanometers. People cannot see that light with the naked eye. Certain animal species, such as mosquitoes, venomous snakes, and piranhas, can. That vision helps them catch prey.
With these lenses, scientists provide insight into what that looks like. The lenses use Upconversion. This is a process in which light with low energy – such as infrared – is converted into light with higher energy, such as visible light. For the study, the scientists chose special nanoparticles that absorb infrared light and convert it into visible red, green, or blue light.
Participants who wore the lenses could see a kind of flash of light that indicated the direction from which the infrared light came. That image became clearer when they closed their eyes because eyelids block visible light better than infrared.
Secret Messages and Color Blindness
Scientists emphasize that the lenses are not sensitive enough for thermal vision. That is seeing differences in temperature. This is because warmer objects have longer wavelengths than those used in the lenses.
Future research will focus on this. According to the researchers, secret messages sent via infrared light would then only be visible to people with these special lenses.
The technology could also help people with color blindness. The lenses could then convert wavelengths that these people cannot see into shades that they can see. But further research is needed for this.