A shot of nanoparticles lets mice see in the dark

Injected into their eyes, the particles alter infrared light to make night vision possible.

How it worked: The nanoparticles stick to the eye’s retinal cells, which convert light into electric signals. They turned infrared light, which mice cannot see, into green light, which they can.

Tests: We still haven’t worked out how to get mice to talk, so to check to see whether the nanoparticles worked as expected, the team shined infrared light into their eyes. The pupils of mice given the injection contracted, whereas the control group’s pupils did not. In another test, the mice were allowed to roam around two chambers, one dark and one lit with infrared. The ones that had received the injection spent more time in the dark area (indicating they found the infrared chamber too bright).