02 Apr Night Vision Without Goggles?
By Ruth Alexander, UNE Discovery
Imagine being able to see in the dark, without bulky night-vision goggles strapped to your head. It sounds like science fiction, but researchers have recently developed contact lenses that could one day make this a reality.
The challenge lies in how our eyes work. Humans can only see a small portion of the light spectrum, known as visible light. Beyond that lies infrared light which is completely invisible to us. Until now, seeing in the dark has required external devices like goggles to help us see this infrared light, which can be heavy, expensive, and reliant on power. Traditional night vision goggles also tend to have a very limited field of view, like staring through toilet paper rolls to find what you are looking for.
Contact lens insertion Source: Wikimedia by Etan J.
Enter the latest innovation: soft, wearable contact lenses designed to extend what we can see beyond the range of visible light. These lenses contain tiny particles called nanoparticles that can convert the longer wavelengths of invisible near-infrared light into visible light. In simple terms, they ‘translate’ light our eyes can’t detect into something we can see, no batteries or external power source required!
So, what can these lenses do? Importantly, the contacts do not affect the way the wearer sees normal visible light, and early tests show that people wearing them can detect near-infrared signals and even recognise patterns, like flashing codes. Surprisingly, they can also work with eyes closed, since infrared light is able to pass through eyelids more easily than visible light. Participants were better at detecting infrared flashes when their eyes were shut, as there was less interference from visible light. It’s a small detail, but one that hints at just how different this technology is from anything we currently use.
Even more impressive is the potential to go beyond simple night vision. Researchers were able to tweak their nanoparticles to convert specific infrared wavelengths into specific visible wavelengths, so participants could see different shades of infrared light in different visible colours. This means users could potentially ‘see’ multiple invisible signals at once, opening entirely new ways of interpreting the world around us.
Although it is already possible to buy ‘infrared’ contact lenses online (typically marketed for cheating at card games), these lenses don’t really allow users to see infrared light. Instead, they filter out higher wavelengths of light to make it easier to see light at a desired wavelength, usually one tuned to an invisible ink sold with the contact lenses.
Of course, it’s still early days, and the technology is still a long way off practical use. The lenses don’t yet offer the sharp detail of traditional night-vision systems, and the technology still needs to be refined. Regardless, the future possibilities with this new technology are exciting. From navigating through fog or darkness, to sending hidden signals and even creating new anti-counterfeiting settings, this technology could change how we interact with the world around us. With further refinement and increased sensitivity, this technology could also improve search-and-rescue missions in low visibility, as humans and other warm-blooded animals emit infrared light, so would ‘glow’ faintly.
As research continues, one thing is clear: the future of vision may not be limited by biology alone. With innovations like these, we may soon be seeing a whole new world, one that was always there, just invisible to the naked eye.
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