Eye-hand coordination under the microscope is a fundamental skill to many microsurgical specializations. In this work, we investigate the oculomotor and motor differences between novice and expert surgeons in the classical eye-hand coordination Fitts’ law task. However, the field of view under the microscope is never static or stable due to inherent internal and external artifacts. In this work, we present methodological steps necessary for stabilizing the operation field of view using RANSAC and for defining static areas of interest (i.e., task targets) and dynamic areas of interest using YOLOv8 (i.e., instrument movement). When combined, we observed that under the microscope, eye movements were spatially more focused than hand movements and that experts relied on parafoveal vision when targeting large targets. Our work opens the path to objective and autonomous skill-acquisition assessment in microsurgical expertise.

Microsurgery requires visuomotor coordination under high magnification, where depth and scale are distorted. Understanding how surgeons adapt eye-hand coordination under the surgical microscope is key to advancing microsurgical education. We investigated gaze behavior and performance differences between expert plastic surgeons and novices during microsurgical suturing. An ocular-mounted eye-tracking system magnetically attached to the microscope preserved naturalistic gaze patterns while maintaining authentic spatial and visual conditions. Suturing was decomposed into phases: needle alignment and tissue piercing, pull-through, and knot tying, for phase-specific analysis. Performance was evaluated using the UWOMSA, and perceived workload was measured with the SURG-TLX. Experts completed the overall task faster than novices, exhibited shorter mean fixations overall, and showed the largest event-level advantage during knot tying. Findings indicate that visual strategies in microsurgery are phase-dependent and expertise-specific. In conclusion, ocular-mounted eye-tracking offers a valuable framework for studying microsurgical visuomotor control and developing objective, data-driven approach for microsurgical training.

We examined whether human operators move their eyes earlier to a target before hands when the level of task difficulty increases. We hypothesized that participants would perform less proactive eye movements in the difficult task than in the easy one, as they would need to focus more on their current hand movements. Sixteen university students were recruited to perform the aiming and touching task reciprocally on three paired targets (circles) differing in sizes and distances, while had their eye movements tracked. The movement time, the early eye engagement time (EEET), and the number of eye adjustments were recorded. The EEET was defined as the time that a subject’s eyes fix on a target to the moment that the tool reaches out for it. The movement time increased as the index of difficulty (ID) value increased, echoing with the Fitts’ Law prediction. When aiming to a target with a higher ID, participants’ EEET was longer comparing to when reaching for a target with a lower ID. Participants reduced the movement speed to give themselves a longer time in searching visually for the target information before moving their hands. In contrast to our hypothesis, results suggested a proportional relationship between the task difficulty and the early eye engagement time. Participants also performed an increasing number of eye adjustments over the course of moving from the easy to the hard target. Future research is needed to examine eye hand coordination under the regulation of Fitts’ Law.