Frequency Of Microsaccades Research Articles

Effect of Different Measurement Tasks on the Frequency of Microsaccades

In recent years, several attempts have been made to quantitatively evaluate covert attention using microsaccades. However, several unclear aspects exist regarding the measurement method of microsaccades, and a unified analysis method does not exist. Therefore, the current status is such that the interpretation of the results is divided among the research groups. To address this problem, empirical studies on microsaccades must be accumulated and measured and evaluated using a unified method. Therefore, in this study, to accumulate empirical studies on microsaccades, an experiment was conducted to investigate the effect of the presence or absence of gazing at a fixation point on the interval of occurrence of microsaccades in a measurement task. The participants were 15 healthy young people, and we compared the following two types of measurement tasks. Task-I: The participants freely visually searched a white wall 1 m away for 120 s. Task-II: The participants gazed at a fixation point located 1 m ahead at eye level for 120 s. For the microsaccade detection algorithm, we adopted a method imitating the EK method proposed by Engbert and Kliegl in 2003, divided 120 s of time-series data and analyzed it every 2 s, and subsequently evaluated the time-series data for the entire 120 s by concatenating them. Consequently, the interval of occurrence of microsaccades during Task-II decreased by more than 1 Hz compared with that of Task-I (p<0.05). The study confirmed that the presence or absence of gazing at the fixation point during microsaccade measurement affected the interval of occurrence of microsaccades.

Effect of Alcohol Consumption on the Frequency of Microsaccades

In recent years, as eye movement measurement devices have become relatively cheap, many attempts have been made to quantitatively evaluate covert attention by focusing on microsaccades. However, the measurement of microsaccades still has many unclear points, and a unified analysis method is still lacking. As such, the interpretation of results differs among different research groups. To solve this problem, it is important to conduct empirical studies on microsaccades to evaluate them using a unified method. In this study, we conducted an empirical experiment on the effects of alcohol consumption on microsaccades by temporarily suppressing cerebellar activity with alcohol consumption. The results showed that the frequency of microsaccades was significantly reduced after 30, 50, and 70 min of drinking compared to after drinking (p< 0.05). These results suggest that the decrease in brain function caused by alcohol consumption suppresses the frequency of microsaccades, and that this may be the cause of constriction in the peripheral visual field when drinking.

Transcranial magnetic stimulation to frontal but not occipital cortex disrupts endogenous attention

Covert endogenous (voluntary) attention improves visual performance. Human neuroimaging studies suggest that the putative human homolog of macaque frontal eye fields (FEF+) is critical for this improvement, whereas early visual areas are not. Yet, correlational MRI methods do not manipulate brain function. We investigated whether rFEF+ or V1/V2 plays a causal role in endogenous attention. We used transcranial magnetic stimulation (TMS) to alter activity in the visual cortex or rFEF+ when observers performed an orientation discrimination task while attention was manipulated. On every trial, they received double-pulse TMS at a predetermined site (stimulated region) around V1/V2 or rFEF+. Two cortically magnified gratings were presented, one in the stimulated region (contralateral to the stimulated area) and another in the symmetric (ipsilateral) nonstimulated region. Grating contrast was varied to measure contrast response functions (CRFs) for all attention and stimulation combinations. In experiment 1, the CRFs were similar at the stimulated and nonstimulated regions, indicating that early visual areas do not modulate endogenous attention during stimulus presentation. In contrast, occipital TMS eliminates exogenous (involuntary) attention effects on performance [A. Fernández, M.Carrasco,Curr. Biol.30, 4078-4084 (2020)]. In experiment 2, rFEF+ stimulation decreased the overall attentional effect; neither benefits at the attended location nor costs at the unattended location were significant. The frequency and directionality of microsaccades mimicked this pattern: Whereas occipital stimulation did not affect microsaccades, rFEF+ stimulation caused a higher microsaccade rate directed toward the stimulated hemifield. These results provide causal evidence of the role of this frontal region for endogenous attention.

A-01 Changes in Fixational Eye Movements (FEMs) Following Concussion

Abstract Purpose: Identify changes in fixational eye movement (FEMs) outcomes following concussion and assess the association of FEMs outcomes with clinical outcomes including symptoms, neurocognitive, and vestibular/ocular motor. Methods: Participants included thirty-three individuals (13–27 years old; 54.5% female) diagnosed with concussion within the past 21 days. Concussion diagnosis was determined using current consensus guidelines. A tracking scanning laser ophthalmoscope (TSLO) was used to measure FEMS. Participants completed ImPACT, PCSS, and VOMS. Within-subjects changes in FEMS outcomes were calculated using paired-samples t-tests. A backwards stepwise linear regression to predict days to clearance was utilized with all FEMS outcomes as predictors. Results: MeanDriftH (slope of cumulative drift regression calculated horizontally; mean difference = 0.04; p = 0.03; Cohen’s d = 0.43) and drift proportion significantly changed over time (mean difference = 0.03; p = 0.03, d = 0.44). Average peak velocity of microsaccade (MsPkVel) predicted days to recovery (R = 0.26; p = 0.045; n = 24). MsPkVel and average duration of blink correlated with select reports of nausea on VOMS. Microsaccade frequency (r = −0.36; p = 0.04) correlated with NPC fogginess. Drift amplitude (DriftAmp) correlated with NPC distance (r = −0.41; p = 0.02) and VMS headache (r = 0.35; p = 0.04). MeanDriftH was negatively correlated with verbal memory (r = −0.44; p = 0.01), whereas DriftAmp was positively correlated (r = 0.50; p = 0.003). Bivariate contour ellipse area was correlated (r = 0.43; p = 0.01) with slower reaction time on ImPACT. Conclusions: FEMs outcomes demonstrated significant change and were useful in predicting recovery time following concussion. FEMs measurements may provide brief, objective data to augment current clinical assessment and inform prognosis for recovery. Future researchers should examine FEMS outcomes from pre- to post-concussion and explore age and sex differences.

Characterizing Fixational Eye Motion Variance Over Time as Recorded by the Tracking Scanning Laser Ophthalmoscope.

PurposeThe purpose of this study was to characterize the benign biological variance of fixational microsaccades in a control population using a tracking scanning laser ophthalmoscope (TSLO), accounting for machine accuracy and precision, to determine ideal testing conditions to detect pathologic change in fixational eye motion (FEM).MethodsWe quantified the accuracy and precision of the TSLO, analyzing measurements made by three operators on a model eye. Repeated, 10-second retinal motion traces were then recorded in 17 controls, 3 times a day (morning, afternoon, and evening), on 3 separate days. Microsaccade metrics (MMs) of frequency, average amplitude, peak velocity, and peak acceleration were extracted. Trace to trace, interday, and intraday variability were calculated across all subjects.ResultsIntra-operator and machine variation contributed minimally to total variation, with only 0.007% and 0.14% contribution for frequency and amplitude respectively. Bias was detected, with lower accuracy for higher amplitudes. Participants had an average (SD) microsaccade frequency of 0.84 Hz (0.52 Hz), amplitude of 0.32 degrees (0.11 degrees), peak velocity of 43.68 degrees/s (14.02 degrees/s), and peak acceleration of 13,920.04 degrees/s2 (4,186.84 degrees/s2). The first trace recorded within a session significantly differed from the second two in both microsaccade acceleration and velocity (P < 0.05), and frequency was 0.098 Hz higher in the evenings (P < 0.05). There was no MM difference between days and no evidence of a session-level learning effect (P > 0.05).ConclusionsThe TSLO is both accurate and precise. However, biological inter- and intra-individual variance is present. Trace to trace variability and time of day should be accounted for to optimize detection of pathologic change.

Influence of Task-evoked Mental Workloads on Oculo-motor indices and their connections

The frequency of microsaccades is often used as a measurement of eye movement in order to estimate the level of effort required, because some indices of oculo-motors suggest the level of mental activity. In an experiment involving several task-manipulation levels, ocular information including micros

T71. A DIRECT COMPARISON OF ADHD, ASD AND SCHIZOPHRENIA ON FOUR BASIC OCULAR-MOTOR TASKS: TOWARDS A MODEL OF NEURODEVELOPMENTAL CONTINUUM

BackgroundAccording to the Neurodevelopmental continuum hypothesis, neurodevelopmental disorders such as ADHD, Autism and Schizophrenia, should be conceptualised as lying on a continuum of neurodevelopmental impairment, with the individual disorders reflecting different degrees of abnormal brain development and resulting functional impairment. The model also hypothesizes that these disorders lie on a gradient of severity, suggesting that they might differ to some extent quantitatively but also qualitatively. The severity of neurodevelopmental impairment is also expressed by the severity of cognitive impairment and persistence of functional impairment. The main objective of the present study was therefore to investigate commonalities and differences among the three conditions in various cognitive subdomains using standard ocular-motor paradigms.MethodsFour groups of young adults were included: 21 with Early-Onset Schizophrenia (“SCZ”, 19.7±1.7, 15 males), 26 with Autism Spectrum Disorder (“ASD”, 19.7±1.9, 25 males), 28 with Attention-Deficit/Hyperactivity Disorder (“ADHD”, 19.9±1.4, 15 males), 29 typically developing participants (“TD”, 19.8±1.6, 12 males). Participants were matched on age and full-scale IQ. Eye movements were recorded binocularly at 1000 Hz using the Eye Link 1000+ system while four basic ocular-motor tasks (prosaccade (PRO), antisaccade (ANT), memory-guided saccade (MEM), fixation (FIX)) were administered in counterbalanced order. Eye movements were analysed with Data Viewer 3.2, SPSS 2.3 and MorePower 6.1.ResultsWith respect to standard deviation of saccadic reaction times (SRTSD), ASD and ADHD did not differ from TD for PRO, ANTI, MEM. Conversely, SCZ were significantly more variable in all tasks than TD, but not compared to ASD and ADHD. Furthermore, SCZ were significantly slower than TD and ASD, but not ADHD, in PRO and ANT. Compared to TD, increased percentage of anticipatory saccades was found for MEM in ASD and ADHD, only marginally for PRO in ASD, again for all tasks in SCZ, when compared to both TD and ASD and, in less extent, to ADHD in ANT. A significantly higher percentage of direction errors during ANT was common to all clinical groups, this inhibitory deficit being significantly more severe in SCZ than ASD, but not compared to ADHD. Increased frequency of intrusive saccades during FIX was found in SCZ and ASD, and marginally in ADHD, when compared to TD. As for microsaccades, SCZ and ASD showed a higher frequency of microsaccades for FIX (condition without distractors) and PRO (preceding correct saccades), only SCZ for ANT (both preceding correct saccades and direction errors), compared to TD.DiscussionResults suggest psychomotor slowing, unique for SCZ, as compared to ASD and ADHD, as indicated by increased mean RT in PRO. Conversely, increased anticipatory saccades and direction errors support the presence of inhibition deficits across groups, suggesting a common (pre-)frontal functional impairment. Of note, mean RT discriminates the clinical groups better than ISV, thus emerging as a trans-diagnostic process to the three conditions and, uniquely for SCZ as a deficit independent of the specific tasks administered here. Finally, atypical microsaccadic frequency might suggest common abnormalities in motor response preparation in SCZ and ASD. Across all tasks, participants with SCZ appear more impaired than those with ADHD and ASD, while the performance of ADHD was often in between SCZ and ASD, possibly in line with the idea of a continuum of neurodevelopmental impairment.

Effects of visual blur on microsaccades during visual exploration.

Microsaccades shift the image on the fovea and counteract visual fading. They also serve as an optimal sampling strategy while viewing complex visual scenes. Microsaccade production relies on the amount of retinal error or acuity demand of a visual task. The goal of this study was to assess the effects of blur induced by uncorrected refractive error on visual search. Eye movements were recorded in fourteen healthy subjects with uncorrected and corrected refractive error while they performed a) visual fixation b) blankscene viewing c) visual search (spot the difference) tasks. Microsaccades, saccades, correctly identified differences and reaction times were analyzed. The frequency of microsaccades and correctly identified differences were lower in the uncorrected refractive error during visual search. No similar change in microsaccades was seen during blank-scene viewing and gaze holding tasks. These findings suggest that visual blur, hence the precision of an image on the fovea, has an important role in calibrating the amplitude of microsaccades during visual scanning.

Anticipation of cognitive conflict is reflected in microsaccades: Evidence from a cued-flanker task.

Microsaccade frequency has recently been shown to be sensitive to high-level cognitive processes such as attention and memory. In the present study we explored the effects of anticipated cognitive conflict. Participants were administered a variant of the flanker task, which is known to elicit cognitive interference. At the beginning of each trial, participants received a colour cue providing information about the upcoming target frame. In two thirds of the trials, the cue reliably informed the participants that in the upcoming trial the flankers either matched the central target letter or not. Hence, participants could accurately anticipate whether cognitive conflict would arise or not. On neutral trials, the cue provided no useful information. The results showed that microsaccadic rate time-locked to cue onset was reduced on trials in which an upcoming cognitive conflict was expected. These findings provide new insights about top-down modulations of microsaccade dynamics.

Oculomotor and Inhibitory Control in Dyslexia.

Previous research has suggested that people with dyslexia may have an impairment of inhibitory control. The oculomotor system is vulnerable to interference at various levels of the system, from high level cognitive control to peripheral neural pathways. Therefore, in this work we examined two forms of oculomotor inhibition and two forms of oculomotor interference at high and low levels of the control system. This study employed a prosaccade, antisaccade, and a recent distractor eye movement task (akin to a spatial negative priming) in order to explore high level cognitive control and the inhibition of a competing distractor. To explore low-level control we examined the frequency of microsaccades and post-saccade oscillations. The findings demonstrated that dyslexics have an impairment of volitional inhibitory control, reflected in the antisaccade task. In contrast, inhibitory control at the location of a competing distractor was equivalent in the dyslexic and non-dyslexic groups. There was no difference in the frequency of microsaccades between the two groups. However, the dyslexic group generated larger microsaccades prior to the target onset in the prosaccade and the antisaccade tasks.The groups did not differ in the frequency or in the morphology of the post-saccade oscillations. These findings reveal that the word reading and attentional difficulties of dyslexic readers cannot be attributed to an impairment in the inhibition of a visual distractor or interference from low-level oculomotor instability. We propose that the inhibitory impairment in dyslexia occurs at a higher cognitive level, perhaps in relation to the process of attentional disengagement.

No supplementary evidence of attention to a spatial cue when saccadic facilitation is absent

Attending a location in space facilitates responses to targets at that location when the time between cue and target is short. Certain types of exogenous cues – such as sudden peripheral onsets – have been described as reflexive and automatic. Recent studies however, have been showing many cases where exogenous cues are less automatic than previously believed and do not always result in facilitation. A lack of the behavioral facilitation, however, does not automatically necessitate a lack of underlying attention to that location. We test exogenous cueing in two experiments where facilitation is and is not likely to be observed with saccadic responses. We also test alternate measures linked to the allocation of attention such as saccadic curvature, microsaccades and pupil size. As expected, we find early facilitation as measured by saccadic reaction time when CTOAs are predictable but not when they are randomized within a block. We find no impact of the cue on microsaccade direction for either experiment, and only a slight dip in the frequency of microsaccades after the cue. We do find that change in pupil size to the cue predicts the magnitude of the validity effect, but only in the experiment where facilitation was observed. In both experiments, we observed a tendency for saccadic curvature to deviate away from the cued location and this was stronger for early CTOAs and toward vertical targets. Overall, we find that only change in pupil size is consistent with observed facilitation. Saccadic curvature is influenced by the onset of the cue, buts its direction is indicative of oculomotor inhibition whether we see RT facilitation or not. Microsaccades were not diagnostic in either experiment. Finally, we see little to no evidence of attention at the cued location in any additional measures when facilitation of saccadic responses is absent.

The frequency of catch-up and micro saccades reacts to and predicts stimulus events

The frequency of catch-up and micro saccades reacts to and predicts stimulus events

Eye Behavior Associated with Internally versus Externally Directed Cognition.

What do our eyes do when we are focused on internal representations such as during imagination or planning? Evidence from mind wandering research suggests that spontaneous shifts from externally directed cognition (EDC) to internally directed cognition (IDC) involves oculomotor changes indicative of visual disengagement. In the present study, we investigated potential differences in eye behavior between goal-directed forms of IDC and EDC. To this end, we manipulated the focus of attention (internal versus external) in two demanding cognitive tasks (anagram and sentence generation). IDC was associated with fewer and longer fixations and higher variability in pupil diameter and eye vergence compared to EDC, suggesting reduced visual scanning and higher spontaneous eye activity. IDC was further related to longer blinks, lower microsaccade frequency, and a lower angle of eye vergence. These latter changes appear conducive to attenuate visual input and thereby shield ongoing internal processes from external distraction. Together, these findings suggest that IDC is accompanied by characteristic eye behavior that reflects a decoupling of attention from external events and serves gating out visual input.

Working memory load is reflected in the frequency of microsaccades

Microsaccades are tiny eye movements that individuals perform unconsciously during fixation. Despite the nature and the purpose of microsaccades are still lively debated, recent evidence showed an association between these micro eye movements and higher-order cognitive processes. In two experiments, here we specifically focused on working memory and addressed whether differential memory load could be reflected in a modulation of microsaccade dynamics. In Experiment 1, participants memorized a numerical sequence composed of either two (low-load condition) or five digits (high-load condition), appearing at fixation. The results showed a reduction in the microsaccadic rate in the high-load compared to the low-load condition. In Experiment 2, the numerical sequence was composed of five digits colored all in red or in green. Participants either memorized the five digits (high load) or the color (low load) of the numerical sequence. Hence, visual stimuli were exactly the same in both conditions. Consistent with Experiment 1, microsaccadic rate was lower in the high-load than in the low-load condition. Overall, these findings reveal the presence of a link between working memory and microsaccades.

Alteration of the microsaccadic velocity-amplitude main sequence relationship after visual transients: implications for models of saccade control.

Microsaccades occur during gaze fixation to correct for miniscule foveal motor errors. The mechanisms governing such fine oculomotor control are still not fully understood. In this study, we explored microsaccade control by analyzing the impacts of transient visual stimuli on these movements' kinematics. We found that such kinematics can be altered in systematic ways depending on the timing and spatial geometry of visual transients relative to the movement goals. In two male rhesus macaques, we presented peripheral or foveal visual transients during an otherwise stable period of fixation. Such transients resulted in well-known reductions in microsaccade frequency, and our goal was to investigate whether microsaccade kinematics would additionally be altered. We found that both microsaccade timing and amplitude were modulated by the visual transients, and in predictable manners by these transients' timing and geometry. Interestingly, modulations in the peak velocity of the same movements were not proportional to the observed amplitude modulations, suggesting a violation of the well-known "main sequence" relationship between microsaccade amplitude and peak velocity. We hypothesize that visual stimulation during movement preparation affects not only the saccadic "Go" system driving eye movements but also a "Pause" system inhibiting them. If the Pause system happens to be already turned off despite the new visual input, movement kinematics can be altered by the readout of additional visually evoked spikes in the Go system coding for the flash location. Our results demonstrate precise control over individual microscopic saccades and provide testable hypotheses for mechanisms of saccade control in general.NEW & NOTEWORTHY Microsaccadic eye movements play an important role in several aspects of visual perception and cognition. However, the mechanisms for microsaccade control are still not fully understood. We found that microsaccade kinematics can be altered in a systematic manner by visual transients, revealing a previously unappreciated and exquisite level of control by the oculomotor system of even the smallest saccades. Our results suggest precise temporal interaction between visual, motor, and inhibitory signals in microsaccade control.

Where Does Attention Go When Facilitation is Absent?

Attending a location in space facilitates responses to targets at that location when the time between cue and target is short. Certain types of exogenous cues – such as sudden peripheral onsets – have been described as reflexive and automatic. Recent studies however, have been showing many cases where exogenous cues are less automatic than previously believed and do not always result in facilitation. Given a lack of the behavioural facilitation, we propose to test whether this also suggests a lack of underlying attention to that location. We test exogenous cueing with saccadic responses at a range of cue-target onset asynchronies (CTOAs), but also alternate measures linked to the allocation of attention such as saccadic curvature, microsaccades and pupil size. As expected, we find no early facilitation at short CTOAs, and likewise no impact of the cue on microsaccade direction or pupil size. We do observe a small dip in the frequency of microsaccades after the cue as well as a tendency for saccadic curvature away from the cued location at short CTOAs. We interpret these results as evidence of reduced attention at the cued location that is removed or inhibited too quickly to be measured as facilitation of saccadic responses.

A Microsaccadic Account of Attentional Capture and Inhibition of Return in Posner Cueing.

Microsaccades exhibit systematic oscillations in direction after spatial cueing, and these oscillations correlate with facilitatory and inhibitory changes in behavioral performance in the same tasks. However, independent of cueing, facilitatory and inhibitory changes in visual sensitivity also arise pre-microsaccadically. Given such pre-microsaccadic modulation, an imperative question to ask becomes: how much of task performance in spatial cueing may be attributable to these peri-movement changes in visual sensitivity? To investigate this question, we adopted a theoretical approach. We developed a minimalist model in which: (1) microsaccades are repetitively generated using a rise-to-threshold mechanism, and (2) pre-microsaccadic target onset is associated with direction-dependent modulation of visual sensitivity, as found experimentally. We asked whether such a model alone is sufficient to account for performance dynamics in spatial cueing. Our model not only explained fine-scale microsaccade frequency and direction modulations after spatial cueing, but it also generated classic facilitatory (i.e., attentional capture) and inhibitory [i.e., inhibition of return (IOR)] effects of the cue on behavioral performance. According to the model, cues reflexively reset the oculomotor system, which unmasks oscillatory processes underlying microsaccade generation; once these oscillatory processes are unmasked, “attentional capture” and “IOR” become direct outcomes of pre-microsaccadic enhancement or suppression, respectively. Interestingly, our model predicted that facilitatory and inhibitory effects on behavior should appear as a function of target onset relative to microsaccades even without prior cues. We experimentally validated this prediction for both saccadic and manual responses. We also established a potential causal mechanism for the microsaccadic oscillatory processes hypothesized by our model. We used retinal-image stabilization to experimentally control instantaneous foveal motor error during the presentation of peripheral cues, and we found that post-cue microsaccadic oscillations were severely disrupted. This suggests that microsaccades in spatial cueing tasks reflect active oculomotor correction of foveal motor error, rather than presumed oscillatory covert attentional processes. Taken together, our results demonstrate that peri-microsaccadic changes in vision can go a long way in accounting for some classic behavioral phenomena.

Monocular microsaccades are visual-task related.

During visual fixation, we constantly move our eyes. These microscopic eye movements are composed of tremor, drift, and microsaccades. Early studies concluded that microsaccades, like larger saccades, are binocular and conjugate, as expected from Hering's law of equal innervation. Here, we document the existence of monocular microsaccades during both fixation and a discrimination task, reporting the location of the gap in a foveal, low-contrast letter C. Monocular microsaccades differ in frequency, amplitude, and peak velocity from binocular microsaccades. Our analyses show that these differences are robust to different velocity and duration criteria that have been used previously to identify microsaccades. Also, the frequency of monocular microsaccades differs systematically according to the task: monocular microsaccades occur more frequently during fixation than discrimination, the opposite of their binocular equivalents. However, during discrimination, monocular microsaccades occur more often around the discrimination threshold, particularly for each subject's dominant eye and in case of successful discrimination. We suggest that monocular microsaccades play a functional role in the production of fine corrections of eye position and vergence during demanding visual tasks.

Interactions between target location and reward size modulate the rate of microsaccades in monkeys.

We have studied how rewards modulate the occurrence of microsaccades by manipulating the size of an expected reward and the location of the cue that sets the expectations for future reward. We found an interaction between the size of the reward and the location of the cue. When monkeys fixated on a cue that signaled the size of future reward, the frequency of microsaccades was higher if the monkey expected a large vs. a small reward. When the cue was presented at a site in the visual field that was remote from the position of fixation, reward size had the opposite effect: the frequency of microsaccades was lower when the monkey was expecting a large reward. The strength of pursuit initiation also was affected by reward size and by the presence of microsaccades just before the onset of target motion. The gain of pursuit initiation increased with reward size and decreased when microsaccades occurred just before or after the onset of target motion. The effect of the reward size on pursuit initiation was much larger than any indirect effects reward might cause through modulation of the rate of microsaccades. We found only a weak relationship between microsaccade direction and the location of the exogenous cue relative to fixation position, even in experiments where the location of the cue indicated the direction of target motion. Our results indicate that the expectation of reward is a powerful modulator of the occurrence of microsaccades, perhaps through attentional mechanisms.

Micro and regular saccades across the lifespan during a visual search of “Where’s Waldo” puzzles

Despite the fact that different aspects of visual-motor control mature at different rates and aging is associated with declines in both sensory and motor function, little is known about the relationship between microsaccades and either development or aging. Using a sample of 343 individuals ranging in age from 4 to 66 and a task that has been shown to elicit a high frequency of microsaccades (solving Where’s Waldo puzzles), we explored microsaccade frequency and kinematics (main sequence curves) as a function of age. Taking advantage of the large size of our dataset (183,893 saccades), we also address (a) the saccade amplitude limit at which video eye trackers are able to accurately measure microsaccades and (b) the degree and consistency of saccade kinematics at varying amplitudes and directions. Using a modification of the Engbert–Mergenthaler saccade detector, we found that even the smallest amplitude movements (0.25–0.5°) demonstrate basic saccade kinematics. With regard to development and aging, both microsaccade and regular saccade frequency exhibited a very small increase across the life span. Visual search ability, as per many other aspects of visual performance, exhibited a U-shaped function over the lifespan. Finally, both large horizontal and moderate vertical directional biases were detected for all saccade sizes.