There are many things our simple eyes can not see. The colors most mammals can normally see include only a small percentage of the entire electromagnetic spectrum – the ones equating to wavelengths from 400 to 700 nanometers or the colors of the rainbow.
“We could give humans night vision abilities, without the night vision goggles.”
– Dr. Tian Xue
Extreme shades like infrared and ultraviolet are invisible to us. Hence why our eyes are not able to see long wavelengths of light given off at night. This includes near-infrared (NIR) and infrared (IR) light – both of which are all around us, like the heat people give off or objects that reflect infrared light.
Study author Gang Han explained in a statement:
“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. Because infrared wavelengths are too long to be absorbed by photoreceptors, we are not able to perceive them.”
In the near future, this vision inadequacy may be a thing of the past. Thanks to a multidisciplinary team of researchers at the University of Science and Technology of China who have developed a way to enable mice to see beyond their current visible spectrum of light. In other words, they have figured out how to give mice night vision! They did so by simply inserting nanoparticles into their little eyes.
How It Works:
- The technology uses a simple injection (delivered via droplets) containing nanoantennae – nanoscopic electromagnetic collectors designed to absorb specific wavelengths.
- These tiny particles function, in a sense, as accessories to the photoreceptor cells in the eye, anchoring tightly onto them and capturing the larger wavelengths.
- These particles are able to anchor on thanks to lectin conjugated nanoparticles – the proteins that guide these nanoantennae and “glue” them to the outside of retinal photoreceptors in the eyes.
- Once anchored, the nanoantennae convert NIR into visible green light that can then be observed by the retinal cell.
- Then, the rod or cone absorbs the shorter wavelengths and sends them to the brain for translation.
The procedure produced minimal side effects and the enhanced vision wears off within two months. There are no lingering effects afterwards. The treatment works with structures already found in the eye so nothing changed about the rodents’ ability to see during the day.
How did they know the mice could see in the dark? They exhibited unconscious reactions to infrared light, such as their pupils constricting. In a maze test, the mice were able to distinguish between different shapes, such as triangles and circles. These shapes were found throughout the maze and the mice could tell them apart at nighttime in the same way that they could during the daytime. Furthermore, they did a similar test during the day but by shining infrared patterns onto surfaces of the maze. The mice were even able to see the infrared patterns in the daylight too.
This technology is described in detail, including the study on mice, in a research paper that was recently published in the journal Cell. The best part of all this is, the treatment could potentially be applied to humans someday to give us super-vision. In other words, the days of real-life superheroes are right around the corner!
Not only can it extend our natural vision, but this technique may even be used as a treatment for people who are colour-blind and unable to perceive red. This breakthrough work presents an opportunity to explore neural networks in the brain and potentially assist with vision repair. Han said:
“With this research, we’ve broadly expanded the applications of our nanoparticle technology both in the lab and translationally. These nanoantennae will allow scientists to explore a number of intriguing questions, from how the brain interprets visual signals to helping treat color blindness.”
There is still more testing to be done. The safety of this procedure will be further experimented on using other primates. The scientists believe there is great potential for future applications in which nanotechnology-enhanced humans might have roles in security and military settings. Han concludes:
“We believe that this research is a major advance in the field of biotechnology. This concept-provoking study should pave the way to numerous critical applications via the unique creation of mammalian NIR visual ability and have high translational potential. Moreover, it is very likely that the sky may look very differently both at night and in daytime. We may have the capability to view all the hidden information from NIR and IR radiation in the universe which is invisible to our naked eyes.”