The device can be operated untethered, with this first revision running for two to three hours on a single charge. The unit can also be operated while charging. HoloLens can undertake spatial mapping of an environment and then project holograms onto this environment. Holograms can also be anchored to particular spaces within a spatially mapped area. Capability such as this could be useful in a variety of environments; for example, training providers could use it to create training scenarios that are truly in context within a given environment. The unit can also be operated by people who wear glasses or contact lenses.