Human night vision could in the future become possible thanks to breakthrough research detailed today by scientists from the University of Massachusetts.
By harnessing nanotechnology, scientists have made it possible to convert near-infrared light into a wavelength easily seen by the human eye, which could one day enable us to see clearly at night without having to resort to night vision goggles.
“When we look at the universe, we see only visible light,” said principal investigator Gang Han, from the University of Massachusetts Medical School.
“But if we had near-infrared vision, we could see the universe in a whole new way. We might be able to do infrared astronomy with the naked eye or have night vision without bulky equipment.”
The work involves the development of a nanomaterial made using what are known as upconversion nanoparticles (UCNPs). These are capable of converting low-energy photons found in near-infrared light into higher energy light in the wavelength visible to the human eye.
This material would have the same benefits for all mammalian eyes – and researchers have already demonstrated that it works, just not in humans. They have successfully injected the material into the eyes of mice, giving them the ability to see near-infrared light – and proving it through a series of navigation tests.
On the road to human night vision
The research, which is being presented today at the American Chemical Society Fall 2019 National Meeting & Exposition, marks a key step in Han and his colleagues’ work towards human night vision.
Earlier in the year, the researchers successfully gave mice night vision using UCNPs in research that was published to considerable interest. But there was a drawback that could pose an issue for its use in humans: the UNCPs were made using rare earth elements erbium and ytterbium.
Although these remained in the first test mice’s eyes for 10 weeks without apparent side-effects, Han and his team were concerned that they could cause both health and performance issues in humans.
“The UCNPs in our published paper are inorganic, and there are some drawbacks there,” said Han.
“The biocompatibility is not completely clear, and we need to improve the brightness of the nanoparticles for human use.”
Their solution was to redevelop the night vision material using organic dyes, which would be safer for human use. Today’s presentation, which will culminate in a press conference streamed online later today, demonstrates the successful development and application of this dye in mice.
These organic dyes not only produce a brighter light, in either blue or green, but will be easier to pass the rigorous regulatory hurdles required for their use in humans than their inorganic forbear.
The next steps
Having successfully developed the dye, the researchers believe it could have human applications not only to give recipients night vision, but as a potential treatment for certain types of eye disease.
“We’re actually looking at how to use near-infrared light to release a drug from the UNCPs specifically at the photoreceptors,” said Han.
However, while humans remain the ultimate goal, the researchers plan first to augment the night vision abilities of dogs – which they believe could also bring real-world benefits.
“If we had a super dog that could see near-infrared light, we could project a pattern onto a lawbreaker’s’ body from a distance, and the dog could catch them without disturbing other people.”