They were on the killer binders the cool kids carried to middle school, and they make appearances on government-issued IDs. The very idea of their existence has captured sci-fi writers’ imaginations for decades. Holographic images—occasionally misunderstood, often used for projects both mundane and complex—utilize basic tricks of light and photographic impression that have been in wide use since the 1960s.
More information: http://thecreatorsproject.vice.com/blog/how-holograms-will-help-us-see-the-invisible