The Dangers of Optical Illusions

"Audi's luxury vehicles include a neat night-vision system that will automatically warn drivers about hazards on the road," notes Gizmo. "And to drive home just how life-saving it can be, the company's ad agency created a brilliant billboard in an airport with a secret hazard that was only revealed to passengers when they got closer and closer. Using a physical phenomenon called accommodation, the ad cleverly manipulated how the human eye focuses." Read more and see the ad.