neutral) expressions (Schurgin et al.,). These findings suggest that D, I, and R fixations may serve distinct perceptual functions during natural viewing, depending on the semantic nature of the target object. Future research should test this hypothesis by systematically manipulating object semantics and measuring how D, I, and R proportions vary. This could involve controlled experiments where object meaning, relevance, or contextual associations as well as low- and mid-level features are altered independently within the same stimuli. Furthermore, we found that specific predictions of D, I, and R fixations outperform the performance of a generic model including all fixations. [...] The current data show that this exploration is predominantly driven by high-level features, while Inspection fixations—successive fixations on the same object—are more dependent on geometric mid-level features. This suggests that semantic features are particularly important for the salience of extrafoveal targets, whereas subsequent fixations on a currently foveated object more strongly depend on geometric properties. Future research should use the D, I, R framework to explore such differences in feature weights in more depth to further test functional implications of D, I, and R fixations. Past research suggests a shift from a global to a focal processing mode across viewing time, indicated by a decrease in saccadic amplitudes and increase of fixation durations (Ito et al.,; Pannasch et al.,; Unema et al.,). Our results corroborate and extend these findings by showing an increase in fixation duration across D, I, and R as well as a descending frequency of Detection fixations and an ascending but quickly plateauing frequency of Inspection fixations. [...] is driven by Detection fixations and does not hold for Return fixations. Return fixations on the contrary seem to be restricted to close-by objects early in a trial and the corresponding saccades triple their amplitudes over the course of the first two seconds. Future research should use the D, I, R scheme to determine in how far this change is due to dynamic changes in (relative) Return saliency of peripheral objects, versus an effect of possible Return locations building up with exploration. Finally, we found shorter trial durations increase the proportion of Detections and decreases that of Inspections. This finding is in line with a hypothesized faster shift from exploitation to exploration when the overall viewing time is restricted. [...] An alternative explanation could be that the increased pace of exploration, with Detections spread across more objects and fewer Inspections, may lead to incomplete processing and therefore require more Returns, akin to regressions in reading (Engbert et al.,; Vitu & McConkie,). By providing an easily accessible and ready-to-use algorithm for the D-I-R classification we hope this classification approach will be adopted and prove useful for researchers from diverse fields, such as cognitive science, neuroscience, basic and applied vision research. For instance, future research could investigate whether Detection, Inspection and Return fixations and saccades rely on partially distinct neural processes. Some have suggested separate neural streams to be associated with distinct visual processing modes; the dorsal stream favouring a global processing of the visual space appropriate for exploration, and the ventral stream, responsible for a more central inspection of objects appropriate for exploitation (Sheth & Young,; see also Unema et al.,). To identify D, I, and R fixations, we used pixel masks of objects in the images. [...] The present findings provide evidence for systematic and reliable differences between Detection, Inspection and Return fixations and point to potentially diverging functional roles. Future studies should test the functional significance of each type of fixation in targeted experiments, e.g., probing the effect of working memory load or individual capacity on the proportion of R fixations. Future research could also investigate how individual differences in gaze behaviour (e.g., Broda & de Haas,; de Haas et al.,; Linka & de Haas,) are reflected in D, I, and R fixations and how they vary across age (Helo et al.,; Krishna et al.,; Linka et al.,). Further, oculomotor metrics like saccadic velocity and acceleration may reveal further facets of D, I, and R fixations and the differences between them. Finally, the D, I, R schema introduced here shows an interesting parallel to the well-established fixation taxonomy in reading research. [...] Finally, the D, I, R schema introduced here shows an interesting parallel to the well-established fixation taxonomy in reading research. First fixations on a word may be compared to object Detection fixations, refixations of a word to Inspection fixations and regressions to previous words in a text to Return fixations (Engbert et al.,; Vitu & McConkie,). While dominant models of eye movements during reading emphasize the role of lexical and linguistic factors to explain e.g., regressions (Engbert et al.,; Reichle et al.,), future research may probe whether there is mechanistic overlap between D, I, R patterns during scene viewing and corresponding viewing patterns during reading. Taken together, we find that the D, I, and R classification algorithm captures systematic and reliable differences between subgroups of fixations with diverging salience and dynamic profiles, suggesting they may map onto distinct functional classes of fixations. The approach has already been successfully applied to dynamic stimuli and for static stimuli without annotations, the D, I, and R classification can be approximated in a content-agnostic manner with a simple spatial heuristic.