**6.1 Brief history of VR and AR**

The creation of the first head-mounted display (HMD), which Ivan Sutherland dubbed the "Sword of Damocles," in the 1960s is the beginning of the history of virtual reality and augmented reality. Since then, the market for consumer VR devices like the Oculus Rift, HTC Vive, and PlayStation VR has grown significantly. In a similar vein, advances in AR can be seen in the development of AR headsets like Microsoft's HoloLens and Magic Leap One and smartphone-based augmented reality experiences like Pokémon Go [45].
