We humans can only see a certain portion of the electromagnetic spectrum that we dub visible light, although other creatures can perceive more of the spectrum, like birds which can see ultraviolet light and snakes which can detect infrared radiation. We can see in infrared through the use of tools like night vision goggles (or to give them their more accurate name, thermal imaging cameras) but now scientists have achieved something far more impressive and frankly terrifying: they have used nanotechnology to give mice infrared vision.
The scientists, who are apparently unafraid of a super-rodent uprising, injected mice with nanoparticles that gave the creatures infrared vision for up to 10 weeks from just one treatment. The mice could see the visible spectrum as normal but got the bonus of infrared vision as well, with enough accuracy that they could distinguish between different shapes using infrared.
The team was a multidisciplinary group of scientists led by Xue and Jin Bao at the University of Science and Technology of China and Gang Han at the University of Massachusetts Medical School, and their aim was to develop the nanotechnology to work in harmony with the existing structures of the eye.
“When light enters the eye and hits the retina, the rods and cones — or photoreceptor cells — absorb the photons with visible light wavelengths and send corresponding electric signals to the brain,” Han explained in a statement. “Because infrared wavelengths are too long to be absorbed by photoreceptors, we are not able to perceive them.”
To overcome the limitations of the photoreceptors, the team created nanoparticles which anchored to the receptors and converted infrared light to a visible light signal. The infrared light hits the retina of the eye and is transformed by the nanoparticles into a shorter wavelength, which is interpreted by the brain as regular visible light.
“In our experiment, nanoparticles absorbed infrared light around 980 nm in wavelength and converted it into light peaked at 535 nm, which made the infrared light appear as the color green,” Bao said in the same statement. The mice were able to use this converted visible light signal to navigate a maze using both visible light and infrared light at the same time.
There were a few side effects, like cloudy corneas which some mice experienced but which cleared up within a week. The team thinks that the same technology could potentially work for humans, not only for extending our natural vision but also for treating people with color vision deficits. Super-vision could be just around the corner.
The paper is published in the journal Cell.
