Background: Gaze behavior differences between expert and novice surgeons have been established in previous studies mainly from the general surgery field.Limited information is available about surgeon’s visual attention during microsurgery procedures where surgical microscope is used. Methods: 4 experts and 3 novices performed 37 independent sutures under the surgical microscope.Eye movements of surgeons and scene video of the surgical performance were recorded.Total suturing time and subtask times were compared between level of expertise.We defined three discrete surgical actions and examined eye gaze (fixation) directly related to each of these actions.Fixation duration (measured by total,pre-action,and post-action duration) were compared between expert and novice, over 3 subtasks (piercing, exiting and cutting) and between pre- and post-action phases. Results: Expert surgeons completed the suture with shorter total time than novices.On average,expert displayed longer fixation time than novice.Experts also maintained their visual engagement constantly over the 3 level of subtask in comparison to novices who required a longer fixation time for the challenging subtask (piercing).Experts use longer pre- than post-action fixation, and this pattern is distributed over all three subtasks.This gaze engagement strategy was not shown in novices. Conclusions: The action-related fixation can be used to evaluate microsurgeons’ level of expertise and in surgical education for gaze training.