As practical applications of virtual reality begin to replace flat screens, designers need to consider how to adapt the principles of UX to a 3D world. In the same way that the shift from print to digital prompted designers to develop new skills to work in a growing medium, designing for VR requires designers to consider new forms of input, physicality, working with different senses, and how to make UI work in three dimensions.
Source: UX 101 for Virtual and Mixed Reality — Part 1: Physicality