The Modern Sword of Damocles: Risks and Rewards of AR glasses

The ancient Greek parable of the sword of Damocles features Dionysius II, the despotic king whose wealth and power are overshadowed by his fear of capital retribution from his citizenry. One day, a courtier named Damocles began to heap praise upon the ruler: "How happy you must be! You have here everything that any man could wish." In response, Dionysius offered him the throne for a day, and Damocles could barely contain his excitement. After indulging in kingly luxuries for a time, Damocles looked up to see a razor-sharp sword dangling perfectly above his head, held up only by a single horsehair. He quickly returned the throne, realizing that the enviable life of a king was shadowed by a constant, looming threat.

This story must have been in the heads of Professor Ivan Sutherland and his team at the University of Utah when, in 1968, they created what is widely considered the first augmented reality system. The head-mounted display was so large and unruly that it had to be hung from the ceiling, earning the nickname "the sword of Damocles." The device presented basic wireframe graphics through semitransparent lenses, allowing users to see their physical surroundings while simultaneously viewing digital overlays. Crucially, it included components that enabled head tracking technology. Today, head tracking and physical transparency are pillars of AR technology and differentiated from other similar technologies like virtual reality — though there is oftentimes some overlap.