https://doi.org/10.53453/ms.2026.6.11
Eye movements and pupillary dynamics in attention deficit
hyperactivity disorder: current perspectives and future directions
Danilas Pavilionis
1
, Austėja Kairiūkštytė
2
1
Lithuanian University of Health Sciences, Faculty of Medicine, Kaunas, Lithuania
2
Lithuanian University of Health Sciences Kauno klinikos, Department of Psychiatry, Kaunas, Lithuania
Abstract
Introduction. Attention deficit hyperactivity disorder (ADHD) is a common neurodevelopmental condition
characterized by persistent patterns of inattention, hyperactivity, and impulsivity. While diagnosis currently relies on
subjective behavioral assessments, there is a growing interest in objective physiological markers. Eye movements and
pupillary dynamics, which are closely linked to the locus coeruleus–norepinephrine system, have emerged as
promising candidates for improving diagnostic accuracy.
Materials and methods. A literature review was conducted using the PubMed database. A total of 21 articles
published between 2013 and 2024 were selected and analyzed, focusing on eye-tracking, pupillometry, and their
application in ADHD populations.
Results . Research indicates that individuals with ADHD often exhibit specific oculomotor abnormalities, including
increased antisaccade errors and gaze instability. Furthermore, atypical pupillary responses, such as altered task-
evoked dilation and increased baseline variability, reflect underlying deficits in arousal regulation and attentional
effort. Integrating both measures provides a more comprehensive neurocognitive profile than single-method
approaches. However, factors such as developmental changes, medication, and comorbidities can influence these
physiological signals.
Conclusions. Although eye movements and pupillometry provide valuable objective data on core ADHD deficits,
standardized protocols and age-specific norms are still required before these tools can be implemented in routine
clinical practice.
Keywords: ADHD, eye-tracking, pupillometry, oculomotor control, physiological markers.
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Medical Sciences 2026 Vol. 14 (4), p. 117-123, https://doi.org/10.53453/ms.2026.6.11
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1. Introduction
Attention Deficit Hyperactivity Disorder (ADHD) is a
common neurodevelopmental condition characterized
by persistent patterns of inattention, hyperactivity, and
impulsivity that interfere with daily functioning and
development. It affects both children and adults, with
global prevalence estimates suggesting approximately
4 - 5% in children and around 2.5 - 3% in adults (1).
ADHD is associated with significant impairments in
academic, occupational, and social domains, making
accurate identification and management essential (2).
Despite its clinical significance, the diagnosis of
ADHD remains largely based on subjective
assessment methods. Current diagnostic practices rely
on behavioral observations, clinical interviews, and
standardized rating scales, typically guided by criteria
such as those outlined in diagnostic manuals. While
these approaches are widely used, they are inherently
dependent on self-report or informant-report
measures, which may be influenced by bias, recall
inaccuracies, and variability across contexts. This
subjectivity can contribute to both underdiagnosis and
overdiagnosis, as well as inconsistencies in clinical
decision-making (3).
In response to these limitations, there has been
growing interest in identifying objective physiological
markers that could support or enhance ADHD
assessment. Biomarkers, defined as measurable
indicators of biological processes, offer the potential
to provide more reliable and quantifiable insights into
underlying neurophysiological mechanisms (3). In
particular, measures derived from eye movements and
pupillary dynamics have gained attention due to their
close links with attentional control, cognitive
processing, and arousal regulation. These
physiological signals may reflect alterations in neural
systems implicated in ADHD and therefore represent
promising candidates for objective assessment (4,5).
2. Materials and methods
A literature search was conducted using
the PubMed database to identify relevant studies. The
search was performed using various keywords and
their combinations, including: ADHD, attention
deficit hyperactivity disorder, eye movements,
pupillary dynamics, oculomotor control, eye tracking
and physiological markers. Only articles published
in English were selected, with priority given to
publications from the last five years to ensure the
inclusion of current findings. For this review, 21
articles published between 2013 and 2024 were
analyzed.
3. Results
3.1. Neurobiological Basis of ADHD
The neurobiological foundations of ADHD are closely
linked to disruptions in brain systems responsible for
attention, cognitive control, and behavioral regulation.
A central component of these impairments involves
deficits in executive functions, which include
processes such as inhibitory control, working memory,
cognitive flexibility, and sustained attention.
Individuals with ADHD often demonstrate difficulties
in suppressing inappropriate responses, maintaining
goal-directed behavior, and regulating attention over
time, reflecting underlying dysfunction in fronto-
striatal and fronto-parietal neural networks (6).
At the neurochemical level, ADHD has been strongly
associated with alterations in catecholaminergic
systems, particularly those involving dopamine and
norepinephrine. Dopamine plays a key role in reward
processing, motivation, and reinforcement learning,
while norepinephrine is critical for attention regulation
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and arousal. Dysregulation of these neurotransmitters
is thought to contribute to the core symptoms of
ADHD, including impaired attention, increased
impulsivity, and variability in cognitive performance
(7). This is further supported by the effectiveness of
pharmacological treatments, such as stimulant
medications, which act by increasing the availability
of dopamine and norepinephrine in the brain (8).
An important system underlying these neurochemical
processes is the Locus coeruleus–norepinephrine
system, which plays a central role in modulating
arousal, attention, and cognitive effort. The locus
coeruleus, a small nucleus in the brainstem, regulates
the release of norepinephrine across widespread
cortical regions and is closely linked to fluctuations in
attentional states (9). Notably, activity in this system
has been associated with physiological markers such
as pupil dilation, providing a potential bridge between
neurobiological mechanisms and observable
measures. In ADHD, atypical functioning of this
system may lead to difficulties in maintaining optimal
levels of arousal, resulting in either under- or over-
responsiveness to environmental demands (10). It is
also important to consider that oculomotor control and
pupillary responses undergo significant
developmental changes, which may influence findings
across different age groups (11).
3.2. Eye Movements in ADHD
Eye movements provide a valuable window into
cognitive and attentional processes, as they are closely
linked to underlying neural mechanisms of perception,
attention, and executive control. In the context of
ADHD, eye-tracking has emerged as a useful method
for examining subtle impairments in oculomotor
control and attentional regulation (12).
3.2.1. Types of Eye Movements
Several fundamental types of eye movements are
commonly studied in cognitive and clinical research.
Saccades refer to rapid, ballistic movements of the
eyes that shift gaze from one point to another, enabling
efficient exploration of the visual environment. In
contrast, smooth pursuit movements allow the eyes to
steadily follow a moving object, requiring continuous
coordination between sensory input and motor output.
Additionally, fixations represent periods during which
the gaze is relatively stable, allowing for detailed
visual processing and information encoding. The
coordination and control of these eye movements are
essential for effective attention and cognitive
functioning (13).
3.2.2. Oculomotor Abnormalities in ADHD
Research has identified several oculomotor
abnormalities in individuals with ADHD, particularly
in tasks requiring inhibitory control and sustained
attention. One of the most widely studied paradigms is
the antisaccade task, in which individuals are required
to suppress a reflexive gaze toward a stimulus and
instead look in the opposite direction. Individuals with
ADHD tend to exhibit higher rates of antisaccade
errors, reflecting deficits in inhibitory control (14).
In addition to increased error rates, prolonged or more
variable reaction times have been observed in saccadic
tasks, indicating inconsistencies in attentional
engagement and processing speed (14). Furthermore,
individuals with ADHD often display more impulsive
gaze behavior, characterized by frequent, rapid, and
less controlled eye movements. These patterns suggest
difficulties in maintaining stable attentional focus and
regulating responses to external stimuli, consistent
with broader executive function impairments (15).
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3.2.3. Eye-Tracking Tasks Used in Research
A variety of experimental paradigms have been
employed to investigate eye movement behavior in
ADHD. Go/No-Go tasks are commonly used to assess
inhibitory control, requiring participants to respond to
certain stimuli while withholding responses to others.
Eye-tracking measures in these tasks can reveal
impulsive saccades and difficulties in response
suppression (15).
Visual search tasks are used to evaluate attentional
allocation and efficiency, requiring individuals to
locate a target among distractors. In ADHD, these
tasks often reveal less efficient search strategies and
increased distractibility (16). Additionally, reading
paradigms provide insight into real world attentional
processes, as they involve coordinated eye
movements, fixations, and regressions. Individuals
with ADHD may demonstrate atypical reading
patterns, including shorter fixation durations and
increased gaze variability, reflecting challenges in
sustained attention and information processing (17).
3.3. Pupillometry and ADHD
Pupillometry, the measurement of pupil size and its
dynamic changes, has gained increasing attention as a
non-invasive method for assessing cognitive and
neurophysiological processes. In the context of
ADHD, pupillary responses are particularly relevant
due to their close association with attentional control,
arousal regulation, and underlying neuromodulatory
systems (4).
3.3.1. Physiology of Pupil Dilation
Pupil size is primarily regulated by the autonomic
nervous system, reflecting the balance between
sympathetic (dilatory) and parasympathetic
(constrictive) activity. Beyond its basic function of
controlling light intake, pupil dilation is strongly
linked to cognitive and emotional processes. In
particular, changes in pupil size have been associated
with attentional effort, mental workload, and arousal
states (18).
A key neurobiological mechanism underlying these
changes involves the Locus coeruleus–norepinephrine
system, which modulates arousal and attention
through widespread projections across the brain.
Activity in this system correlates with fluctuations in
pupil diameter, making pupillometry a useful indirect
marker of central nervous system activity. As such,
pupil dynamics provide a measurable link between
physiological arousal and cognitive functioning (10).
3.3.2. Pupillary Responses in ADHD
Research examining pupillary responses in individuals
with ADHD has identified several patterns suggesting
atypical regulation of arousal and attention. One
commonly studied parameter is baseline pupil size,
which reflects tonic levels of arousal. Some studies
report differences in baseline pupil diameter in
individuals with ADHD, although findings are not
entirely consistent across the literature (19). These
inconsistencies may reflect differences in task design,
variability in cognitive demands, and the influence of
transient factors such as fatigue and motivation.
Another important measure is task-evoked pupil
dilation, which reflects cognitive effort and processing
demands. Individuals with ADHD may show altered
pupillary responses to cognitive load, including either
reduced or more variable dilation during demanding
tasks. This variability may indicate difficulties in
sustaining consistent levels of attentional engagement
(4).
Additionally, increased variability in pupil size over
time has been observed in ADHD populations,
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suggesting instability in arousal regulation. This raises
the question of whether these measures reflect stable
characteristics of ADHD or dynamic fluctuations in
cognitive state. However, it is important to note that
pupillary responses are highly sensitive to external
factors such as lighting conditions, emotional state,
and fatigue, which can complicate interpretation (19).
3.4. Integration: Eye Movements and Pupillometry
Eye movements and pupillary responses reflect
partially distinct but complementary aspects of
neurocognitive functioning. Oculomotor measures,
such as saccadic control and fixation stability,
primarily capture executive processes, including
inhibitory control and attentional allocation. In
contrast, pupillary dynamics are closely associated
with arousal regulation and neuromodulatory activity,
particularly involving the Locus coeruleus–
norepinephrine system. By combining these measures,
researchers can obtain a more integrated profile of
attentional performance, encompassing both control-
related and state-dependent processes (15).
3.4.1. Multitask Approaches in Research
Recent studies increasingly employ multitask
paradigms that simultaneously engage multiple
cognitive domains - such as sustained attention,
inhibitory control, and working memory - while
synchronizing the recording of eye movements and
pupillary dynamics. In ADHD research, this
multimodal approach is particularly valuable, as it
enables real-time observation of the interaction
between oculomotor behavior and arousal systems,
capturing the moment-to-moment variability
characteristic of the disorder. By integrating these
measures, researchers can identify subtle attentional
control deficits that often remain undetected when
using isolated assessment methods (20).
3.4.2. Advantages Over Single-Method Approaches
The integration of multiple physiological measures
offers several advantages over single-method
approaches. First, it increases the sensitivity of
detecting subtle differences between individuals with
ADHD and control groups. Second, it enhances the
ecological validity of findings by capturing multiple
dimensions of cognitive functioning simultaneously.
Third, combining modalities may improve the
robustness and reliability of potential biomarkers by
reducing the influence of noise or confounding factors
specific to a single measure (15,20).
However, despite these advantages, challenges
remain. Differences in experimental design, data
processing methods, and analytical approaches across
studies limit direct comparability. Furthermore, the
complexity of integrating multimodal data requires
advanced analytical techniques, which are not yet
standardized in clinical research.
3.5. Clinical Implications
The growing body of research on eye movements and
pupillary dynamics raises important questions
regarding their potential role in the clinical assessment
of ADHD. Although current diagnostic practices rely
primarily on behavioral evaluations and subjective
reporting, the integration of physiological measures
may offer valuable complementary information (3).
Integrating eye-tracking and pupillometry into clinical
practice offers a path toward more objective ADHD
assessment by providing quantifiable, real-time data
on core deficits such as inhibitory control and arousal
regulation. These tools may facilitate earlier
identification of subtle neurobiological markers before
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behavioral symptoms fully manifest, enabling timely
interventions that improve long-term functional
outcomes. At the same time, these measures are
intended to complement, rather than replace,
traditional diagnostic methods, and further research
remains essential to establish the standardized
protocols, normative databases, and diagnostic
thresholds required for clinical use (15,20). However,
these measures do not yet meet the criteria for
clinically valid biomarkers and lack sufficient
specificity for ADHD.
3.6. Limitations of Current Research
Despite promising results, several limitations
constrain the clinical applicability of eye-tracking and
pupillometry in ADHD research. Small sample sizes
often reduce statistical power and limit the
generalizability of findings, while significant
methodological variability, including differences in
task paradigms and data analysis, hinders cross-study
comparisons. Furthermore, pupillary measures are
highly sensitive to environmental noise, such as
lighting, and individual factors like fatigue or
medication. Finally, the high prevalence of
comorbidities, such as anxiety or learning disabilities,
complicates the identification of ADHD-specific
biomarkers, making it difficult to isolate the disorder's
unique effects on oculomotor and arousal regulation
(18,21).
4. Conclusion
Eye-tracking and pupillometry offer a promising,
objective approach to enhancing ADHD assessment
by providing quantifiable data on executive control
and arousal regulation. While traditional diagnostic
methods are still essential, these physiological markers
can bridge the gap between subjective observation and
neurobiological reality. Moving forward,
standardizing protocols and establishing age-specific
norms will be crucial for clinical implementation.
Ultimately, integrating these tools could lead to more
precise diagnosis and better-targeted interventions for
individuals with ADHD.
References
1. Popit S, Serod K, Locatelli I, Stuhec M.
Prevalence of attention-deficit hyperactivity disorder
(ADHD): systematic review and meta-analysis. Eur
Psychiatry 2024; 67(1): e68.
2. Cherkasova MV, Roy A, Molina BSG, Scott
G, Weiss G, Barkley RA, et al. Review: Adult
Outcome as Seen Through Controlled Prospective
Follow-up Studies of Children With Attention-
Deficit/Hyperactivity Disorder Followed Into
Adulthood. J Am Acad Child Adolesc Psychiatry
2022; 61(3): 378–391.
3. Faraone SV, Banaschewski T, Coghill D,
Zheng Y, Biederman J, Bellgrove MA, et al. The World
Federation of ADHD International Consensus
Statement: 208 Evidence-based conclusions about the
disorder. Neurosci Biobehav Rev 2021; 128: 789–818.
4. Wainstein G, Rojas-Líbano D, Crossley NA,
Carrasco X, Aboitiz F, Ossandón T. Pupil Size Tracks
Attentional Performance In Attention-
Deficit/Hyperactivity Disorder. Sci Rep 2017; 7(1):
8246.
5. Lee DY, Shin Y, Park RW, Cho SM, Han S,
Yoon C, et al. Use of eye tracking to improve the
identification of attention-deficit/hyperactivity
disorder in children. Sci Rep 2023; 13(1): 14469.
6. Hoogman M, Bralten J, Hibar DP, Mennes M,
Zwiers MP, Schweren LSJ, et al. Subcortical brain
volume differences in participants with attention
deficit hyperactivity disorder in children and adults: a
Journal of Medical Sciences. 18 Jun, 2026 - Volume 14 | Issue 4. Electronic - ISSN: 2345-0592
122
cross-sectional mega-analysis. Lancet Psychiatry
2017; 4(4): 310–319.
7. Perez Custodio RJ, Hengstler JG, Hoon
Cheong J, Jin Kim H, Wascher E, Getzmann S. Adult
ADHD: it is old and new at the same time - what is it?
Rev Neurosci 2023; 35(2): 225–241.
8. Cortese S, Adamo N, Del Giovane C, Mohr-
Jensen C, Hayes AJ, Carucci S, et al. Comparative
efficacy and tolerability of medications for attention-
deficit hyperactivity disorder in children, adolescents,
and adults: a systematic review and network meta-
analysis. Lancet Psychiatry 2018; 5(9): 727–738.
9. Aston-Jones G, Waterhouse B. Locus
coeruleus: From global projection system to adaptive
regulation of behavior. Brain Res 2016; 1645: 75–78.
10. Joshi S, Li Y, Kalwani RM, Gold JI.
Relationships between Pupil Diameter and Neuronal
Activity in the Locus Coeruleus, Colliculi, and
Cingulate Cortex. Neuron 2016; 89(1): 221–234.
11. Huang J, Smorenburg ML, Yep R, Riek HC,
Calancie OG, Kirkpatrick RH, et al. Age-related
changes in pupil dynamics and task modulation across
the healthy lifespan. Front Neurosci 2024; 18:
1445727.
12. Eckstein MK, Guerra-Carrillo B, Miller
Singley AT, Bunge SA. Beyond eye gaze: What else
can eyetracking reveal about cognition and cognitive
development? Dev Cogn Neurosci 2017; 25: 69–91.
13. Leigh RJ, Zee DS. The Neurology of Eye
Movements. 5th ed. Oxford, UK: Oxford University
Press; 2015. (Pastaba: suformuota kaip knyga pagal
pavyzdį).
14. Breuer F, Meyhöfer I, Lencer R, Sprenger A,
Roesmann K, Schag K, et al. Aberrant inhibitory
control as a transdiagnostic dimension of mental
disorders – A meta-analysis of the antisaccade task in
different psychiatric populations. Neurosci Biobehav
Rev 2024; 165: 105840.
15. Levantini V, Muratori P, Inguaggiato E, Masi
G, Milone A, Valente E, et al. EYES Are The Window
to the Mind: Eye-Tracking Technology as a Novel
Approach to Study Clinical Characteristics of ADHD.
Psychiatry Res 2020; 290: 113135.
16. Yıldırım Demirdöğen E, Esin İS, Turan B,
Dursun OB. Assessing sustained attention of children
with ADHD in a class flow video task. Nord J
Psychiatry 2022; 76(7): 497–506.
17. Reichle ED, Liversedge SP, Drieghe D,
Blythe HI, Joseph HSSL, White SJ, et al. Using E-Z
Reader to examine the concurrent development of eye-
movement control and reading skill. Dev Rev 2013;
33(2): 110–124.
18. Mathôt S. Pupillometry: Psychology,
physiology, and function. J Cogn 2018; 1(1): 16.
19. Bellato A, Arora I, Hollis C, Groom MJ. Is
autonomic nervous system function atypical in
attention deficit hyperactivity disorder (ADHD)? A
systematic review of the evidence. Neurosci Biobehav
Rev 2020; 108: 182–206.
20. Liu Z, Li J, Zhang Y, Wu D, Huo Y, Yang J,
et al. Auxiliary Diagnosis of Children With Attention-
Deficit/Hyperactivity Disorder Using Eye-Tracking
and Digital Biomarkers: Case-Control Study. JMIR
Mhealth Uhealth 2024; 12(1): e58927.
21. Sherigar SS, Gamsa AH, Srinivasan K.
Oculomotor deficits in attention deficit hyperactivity
disorder: a systematic review and meta-analysis. Eye
(Basingstoke) 2023; 37(10): 1975–1981.
Journal of Medical Sciences. 18 Jun, 2026 - Volume 14 | Issue 4. Electronic - ISSN: 2345-0592
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