Injected Nanoparticles Could Enable Sight Beyond Visible Spectrum

No mammalian photoreceptor can effectively detect light that exceeds 700 nm, and mammals are unable to see near-infrared (NIR) light or to project aNIR image to the brain. To enable the detection of longer wavelength light in mammals, scientists at the University of Massachusetts Medical School, working with colleagues at the University of Science and Technology of China, developed ocular-injectable photoreceptor-binding upconversion nanoparticles (UCNPs). These nanoparticles, which contain the rare-earth elements erbium and ytterbium, can convert low-energy photons from NIR light into higher-energy green light that mammalian eyes can see. The scientists injected the UCNPs into the eyes of mice. The researchers targeted UCNPs to...