These contact lenses give people infrared vision — even with their eyes shut

Researchers have made contact lenses that give people infrared vision — even with their eyes closed. The lenses are infused with nanoparticles that convert near-infrared light into shorter-wavelength light that humans can see. The result is multi-coloured infrared images that contrast with the monochrome of night-vision goggles. But the lenses don’t amplify light like goggles do, so the infrared light has to be quite bright to be visible.