  Shared gaze visualizations have been found to enhance collaboration and
communication outcomes in diverse HCI scenarios including computer supported
collaborative work and learning contexts. Given the importance of gaze in
surgery operations, especially when a surgeon trainer and trainee need to
coordinate their actions, research on the use of gaze to facilitate
intra-operative coordination and instruction has been limited and shows mixed
implications. We performed a field observation of 8 surgeries and an interview
study with 14 surgeons to understand their visual needs during operations,
informing ways to leverage and augment gaze to enhance intra-operative
coordination and instruction. We found that trainees have varying needs in
receiving visual guidance which are often unfulfilled by the trainers'
instructions. It is critical for surgeons to control the timing of the
gaze-based visualizations and effectively interpret gaze data. We suggest
overlay technologies, e.g., gaze-based summaries and depth sensing, to augment
raw gaze in support of surgical coordination and instruction.
