Figure 5. A schematic of a smart-eye display (in this case, Google GlassTM) as worn by an athlete, and as viewed from the front (left) or from inside the display (right). The display can be either transparent as is the case here or, alternatively, a small monitor-like display that is opaque. Heads-up displays such as these may provide a more unobtrusive display for the relay of biofeedback to the athlete.