**2. Augmented reality vs. virtual reality?**

Whilst augmented reality is technology that overlays on the reality that already exists around us, virtual reality (VR) is a complete replacement of the real world with a simulated one. This means that AR allows us to interact and work with the real world, whilst getting an enhanced input from an informed digital world.

VR has shown to be a great teaching tool. Moglia et al. [6] found that subjects trained on virtual simulators were better than the control group (using conventional methods). An example is the Uro Tainer, a validated simulator for teaching transurethral resection of bladder tumours [7]. VR has not only shown promise in surgery, but also other areas like simulation of shock trauma centres (where surgeons can be trained in high pressured environments) [8] and Virtual Environment for Radiotherapy Training (VERT)—a system built to reduce anxiety in breast cancer patients [9].
