From Geeks are Sexy:
Echizen’s solution was a pair of spectacles which had the option to switch on several LEDs. The resulting light beam is in the near-infrared frequency and is thus invisible to the human eye, but can be detected by camera lenses. The resulting visual noise undermines facial recognition software.
AVG have built the LED technology into their concept prototype and noted that, as shown above, it can certainly be enough to defeat Facebook’s own face recognition. However, it poinst out that even many cellphone cameras used today are sophisticated enough to filter out light at wavelengths invisible to human, thus producing pictures that better replicate what the eye sees.