Impact of eye movement on postoperative optical aberrations and refractive outcomes in LASIK surgery.

Noninvasive ocular particle therapy requires precise eye positioning. While static guidance systems lack gaze flexibility, existing dynamic robot-assisted systems are limited by severe workflow disruptions in shared clinical environments and a lack of kinematic occlusion models to guarantee safety. To overcome these limitations, an eye positioning and monitoring system (EPMS) was developed. A gaze range analysis algorithm and an occlusion zone analytical algorithm for the beam path and cameras were proposed. Furthermore, a mechanical reproducibility assessment quantified the system's performance under busy preoperative disruptions, including powering off/reconnecting and uninstalling/reinstalling. The EPMS mechanical guidance range reached 360° azimuth and 60.1° maximum polar, while identifying specific exclusion zones. Stability tests demonstrated cumulative workflow errors were always ≤ 0.22mm and 0.01° for the guidance module, and ≤ 0.20mm and 0.1° for the monitoring module. Corresponding eyeball rotation deviations were 0.25° (SD 0.13°) in polar and 0.09° (SD 0.07°) in azimuth. The EPMS demonstrates robust reproducibility, validating its adaptability to conventional radiotherapy environments without requiring dedicated ophthalmology treatment rooms.

Pigeons lock their eyes in place during flight.

During the recall of pictorial information, individuals typically exhibit eye movements directed toward the locations they focused on during perceptual encoding. This behavior is thought to support memory retrieval by linking spatial information to cognitive processes. Given the known memory decline associated with healthy aging, investigating age-related changes in eye movements during recall is crucial. We compared the eye movement patterns of older (N = 38, 65-75 years) and younger adults (N = 37, 20-35 years) during different pictorial recall tasks. Both groups tended to look back at the original stimulus locations; however, this effect was less pronounced in older adults. They displayed less systematic and more dispersed fixations across the screen. Moreover, eye position information generalized to novel objects from previously seen categories in both groups. In terms of performance, older adults performed worse than younger adults on an old/new recognition task but not on a task assessing visual detail recall. Older adults rated their mental images as more vivid than younger adults did, which may reflect differences in the perception or interpretation of vividness or subjective bias. The observed pattern of eye behavior, together with the relatively preserved recall performance, suggests that older adults rely less on embodied strategies, consistent with prior findings indicating an age-related shift toward gist-based representations. Overall, our results demonstrate that eye movement behavior during pictorial recall changes with age, highlighting the need for further investigation into the underlying mechanisms and possible consequences of this change. (PsycInfo Database Record (c) 2026 APA, all rights reserved).

Parsing complex dynamic scenes is critical for navigating our visual world, and driving safely is a daily task that requires responding quickly to hazardous events. Theories of driver awareness suggest that drivers need to look at hazards to detect them, particularly in anticipation of hazard onset. Indeed, scene context may guide eye movements to likely hazard locations. However, given the complexity of real road scenes, drivers may rely instead on explicit cues of an impending collision before identifying the correct location. In 2024, we recorded eye position while 30 licensed drivers localized hazards in annotated dashcam footage. On correct trials, drivers started to look at where the hazard will be 2 s before onset, highlighting the importance of anticipatory processes in dynamic scene perception and safe driving. However, hazard-directed looking is not indicative of awareness, as 40% of missed hazards were foveated before response. Our results demonstrate early gaze guidance by scene context, which can help drivers anticipate hazards, an idea consistent with theories of driver awareness and with theories of visual search. However, looking directly at the hazard alone is not necessary or sufficient for hazard awareness and should not be used to index awareness in driver monitoring systems. (PsycInfo Database Record (c) 2026 APA, all rights reserved).

To objectively investigate the effects of blur and disparity cues on accommodative response and microfluctuations (root mean square and low-frequency components), vergence, and pupillary responses to static targets in adolescents with persistent post-concussion symptoms. Thirty-one adolescents with concussions and 32 controls completed the study. Refractive states, eye position (vergence), and pupil size were measured simultaneously using photorefraction (50 Hz) while participants viewed near stimuli for 15 seconds at nine distances ranging from 100 to 25 cm under three viewing conditions: blur and disparity cues (binocular, cartoon movie), blur only (monocular, cartoon movie), and disparity only (binocular, difference of Gaussians target). Participants with concussions showed less accurate accommodative responses (greater accommodative lag) to targets at ≤33 cm than controls did when the targets provided both blur and disparity cues or blur cues only. When disparity-only cues were provided, no significant between-group differences in the accommodative responses were found, but accommodative microfluctuations in participants with concussion were significantly lower than controls at accommodative demands of ≥2.5D (≤40 cm) for the root mean square and ≥2.25D (≤44 cm) for low-frequency components. Vergence and pupillary responses were not significantly different between groups for any viewing conditions or demands. Accommodative response to static near targets was impaired in adolescents with persistent post-concussion symptoms when blur cues were provided. In contrast, vergence and pupillary response to static targets were not impacted at habitual near-viewing distances. This study provides mechanistic insights into accommodative dysfunction in concussion.

ABSTRACTThe impact of executive attention on visual cortical responses depends upon the contrast of input stimuli. Functional neuroimaging has difficulty capturing non‐linear gain modulations of the contrast response function (CRF) and dynamic communication within visual attention networks subserving it. The current study utilized magnetoencephalography (MEG) to examine gain modulation within primary visual cortex (V1) and its connectivity with regions of the dorsal attention network (DAN) during covert attention. Twenty‐five participants completed a spatial covert attention task including neutral and valid cues. MEG was recorded and eye position monitored throughout the task. The CRF and its relevant parameters were modeled using peak V1 evoked responses. Cue‐related alpha‐band desynchronization within contralateral V1 and event‐related spectral perturbations across DAN regions were assessed by wavelet analysis. Weighted phase‐lag index was used to examine DAN–V1 functional connectivity. Valid cue trials produced increased CRF maxima without a significant impact on mid‐saturation or baseline levels. Alpha desynchronization was observed between 10 and 12 Hz during cue presentation in V1. DAN—V1 functional connectivity, most robust within 10–12 Hz, was uniquely associated with larger asymptotic V1 response levels within this range. MEG recordings revealed a pattern of V1 response gain during covert attention associated with DAN—V1 connectivity, advancing our knowledge of this network's frequency‐specific influence over gain modulation within basic visual processing centers. These findings highlight the advantages of MEG for examining interactions between sensory and attentional gain properties of the human visual system, providing a comprehensive understanding of their underlying local and distributed network dynamics.

Impact of Viewing Distance on the Occurrence Rate of Intermittent Exotropia Revealed by Ambulatory Eye Tracking.

In this study, the degree and characteristics of sedation were assessed using the Grint scale for azaperone and acepromazine in 24 dogs, with the effects on heart rate and systemic blood pressure evaluated simultaneously using oscillometry. Posture, palpebral reflex, eye position, relaxation, response, postural resistance, attitude, systolic pressure, diastolic pressure, mean arterial pressure, and heart rate were analyzed using linear mixed-effects models to evaluate the effects of treatment, time, and their interaction. Significant effects of time were observed for all variables (p < 0.001), including systolic, diastolic, and mean arterial pressure, whereas heart rate was not significantly affected by treatment. Based on these results, we conclude that azaperone produces moderate sedation at 20 min after administration, and it does not induce bradycardia or clinically significant hypotension.

The accuracy of eye movements to look at sounds varied across individuals, with median errors spanning a greater than 10-fold range. This range is surprising given that the participants passed screening for normal hearing."Good" vs "poor" sound localizers exhibited differences in their eye movement-related eardrum oscillations (EMREOs)EMREOs differed in both horizontal and vertical sensitivity, for both saccade amplitude and initial eye position, and the differences varied in timing with respect to saccade onset.We interpret the results under the theory that poor sound localization may be a consequence of poor eye movement encoding, without which linking visual and auditory space is likely inaccurate.

Binocular vision requires both eyes to be aligned such that their visual fields overlap. A long-standing premise derived from comparative studies is that the orientation of the orbits determines eye position, and thereby the extension of this overlap, the binocular field. In addition, to produce an accurate neural representation, the binocular field must integrate with the position of retinal high-acuity areas and with the extent of uncrossed retinal projections. It remains unknown, however, whether the binocular field is already formed at the time of eye-opening, as well as when and how it integrates with neuroanatomical visual traits during development. Using the diurnal rodent Octodon degus, a suitable animal model for visual neuroscience, we combined CT-based 3D cranial reconstructions, quantitative measurements of visual-field geometry, whole-mount retinal topography, neural tracing of retinal projections, and behavioral assays to reconstruct the postnatal assembly of the binocular visual system. We show that orbital and ocular orientations shift substantially after birth, broadening the dorsal binocular field; that retinal ganglion cell distributions sharpen into a horizontal visual streak and a defined area centralis; and that ipsilateral projections to the superior colliculus mature in parallel to binocular expansion. These changes coincide with the emergence of binocular-dependent behaviors such as depth discrimination and looming-evoked escape responses. Together, our findings demonstrate that binocular vision emerges through the coordinated alignment of multiple developmental processes across levels of organization.

Oculomotor nerve palsy can be associated with life-threatening pathology, especially when caused by an intracranial aneurysm, requiring urgent recognition and intervention. We report a 57-year-old man with diabetes, hypertension, and dyslipidemia who presented with a three-day history of left ptosis and diplopia, preceded by headache one month earlier. Visual acuity was 6/7.5 in the right eye and 6/10 in the left eye. Examination showed complete left ptosis, a "down-and-out" eye position with preserved abduction, and anisocoria with a 7mm pupil. Initial contrast enhanced CT was unremarkable, but CT angiography revealed a saccular aneurysm of the left internal carotid artery causing mass effect. The patient underwent aneurysm clipping on day five. Postoperatively, visual acuity improved with partial resolution of ptosis, normalization of pupil size, and improved diplopia, highlighting the importance of prompt vascular imaging and timely neurosurgical management.

This study aims to establish a protocol for measuring the postauricular muscle reflex (PAMR) and to characterize both short- and mid-latency responses under controlled conditions in adults with normal hearing. PAMR electromyography was recorded in 43 adults with normal hearing. Auditory stimuli (50 ms, 80-100 dB (A)) were presented at four frequencies (500, 1000, 2000, and 4000 Hz), with systematic variation in stimulation side (ipsilateral/contralateral) and eye position (forward/rotated). The influence of these factors on PAMR amplitude and latency was analyzed using linear mixed-effects models. A short-latency PAMR (10-25 ms) was observed in all but one participant in at least one frequency. Reflex amplitude was significantly affected by stimulation side, eye position, frequency, and intensity. Contralateral stimulation produced stronger responses than ipsilateral stimulation. Additionally, a mid-latency PAMR (37-50 ms) was identified in 91% of participants, exhibiting lower amplitude and a higher detection level compared to the short-latency response. The mid-latency reflex was also significantly influenced by experimental conditions. The data shows that PAMR can be reliably recorded under controlled conditions in normal-hearing adults and that both short- and mid-latency components are influenced by auditory and oculomotor factors. These results provide us with normative data that can serve as a reference for future investigations in clinical populations, such as cochlear implant users and individuals with hearing loss.

Diplopia is a common symptom of interdisciplinary significance that can lead to marked impairment of function. Its causes range from harmless to life-threatening conditions that must be precisely distinguished. For this CME review article, a PubMed search was conducted in an interdisciplinary collaboration of ophthalmologists and neurologists. Systematic history-taking and a structured clinical examination are the basis for topographic-anatomical diagnosis and the differentiation of peripheral and central causes. It is important to distinguish monocular from binocular diplopia. Monocular diplopia persists when one eye is covered and is not dangerous. Binocular diplopia may arise from disturbances at a variety of anatomical levels that can result from many different causes: disturbances of fusion in strabismus, diseases of the eye muscles such as thyroid eye disease or mitochondropathies, orbital trauma, impaired neuromuscular transmission in myasthenia gravis, fascicular or nuclear lesions of the three nerves that supply the extraocular muscles (oculomotor, trochlear, and abducens), supranuclear lesions "above" the cranial nerve nuclei, and cerebellar diseases. The most common causes, together accounting for ca. 70% of cases, are decompensated latent strabismus and cranial nerve palsies, followed by orbital, brainstem, and cerebellar diseases. Diplopia can be accurately diagnosed through a systematic approach that includes precise history-taking and clinical examination of eye position and eye movements. On this basis, there can be a targeted and specific search for the various underlying causes. When the patient's leading symptom is isolated diplopia, the ophthalmologist is generally the specialist to whom the primary care physician should turn next.

Vestibular Dysfunction and Binocular Vision Impairment: A New Clinical Perspective.

Mohs surgeons operate at close working distances under intense surgical illumination. Ocular symptoms, including eye strain and visual fatigue, are commonly reported, yet quantitative data on eye-level exposure to reflected surgical lighting are limited. To quantify reflected surgical lighting at the Mohs surgeon's eye position and identify modifiable operative factors influencing ocular exposure. This observational, device-based experimental study was conducted in a Mohs surgical suite using a simulated surgical model. Reflected illuminance was measured with a calibrated digital lux meter positioned at the surgeon's eye level. Overhead light-emitting diode lighting was fixed 40 inches from the surgical field. Measurements were obtained at eye-to-field distances of 14, 20, and 26 inches across 2 lamp orientations, 2 drape colors, and 3 simulated skin tone categories. Reflected illuminance was highest at shorter working distances, measuring approximately 1.5 to 2.0 times higher at 14 inches than at 20 inches and up to 2 to 3 times higher than at 26 inches. White drapes increased reflected illuminance compared with blue drapes, while behind-the-surgeon lamp positioning reduced exposure compared with perpendicular lamp positioning. Skin tone had minimal impact. Modifiable operative factors significantly influence ocular light exposure and represent low-cost strategies to reduce exposure without compromising visualization.

To characterize intraocular lenses (IOL) position, IOL stability and iris dynamics in eyes with sutureless intrascleral haptic fixated intraocular lenses (SIS-IOLs). This nonconsecutive observational study used ultrasound biomicroscopy to better characterize SIS-IOLs. We included individuals who had SIS-IOL surgery between October 2014 and October 2018. We excluded individuals younger than18 years and those with active uveitis, advanced glaucoma, known ocular syndrome(s), and those with repeated SIS-IOL dislocations before the time of the ultrasound evaluation. Serial ultrasound biomicroscopy were performed in both the seated/supine positions and IOL position and stability were described as our primary outcome. As a secondary outcome, iris mobility was evaluated through dynamic ultrasound biomicroscopy in both the SIS-IOL and posterior chamber IOL (surgery between 2001 and 2019) groups. Analysis of ultrasound biomicroscopy of 22 SIS-IOLs and 10 posterior chamber IOLs, showed that on average, SIS-IOLs were positioned significantly more posteriorly than standard posterior chamber IOLs (aqueous depth = 0.59 vs. 0.48 mm; P < 0.00006)). Over time, SIS-IOLs demonstrated a slight posterior displacement of the IOL (0.18 mm shift posteriorly). Finally, in eyes with SIS-IOLs there was a high degree of iris mobility when compared with the posterior chamber IOL group (Fleiss Kappa 0.887). This study provides ultrasound-based evidence demonstrating a more posterior IOL position with increased iris mobility in eyes with an SIS-IOL. These data provide valuable information which may inform surgeons as they consider IOL selection and surgical technique.

Anisometropia, marked by unequal refractive errors, can cause amblyopia and persistent binocular dysfunction even after visual acuity correction. This study evaluated fine, dynamic, and coarse stereopsis, along with perceptual eye position (PEP), in anisometropic individuals with optimal best-corrected visual acuity (BCVA). In a cross-sectional study, 204 anisometropic patients and 57 age-matched controls underwent synoptophore-based PEP testing and stereopsis assessment, including the Titmus test. Participants were classified as hyperopic, myopic, or astigmatic. Statistical analysis used chi-square and Kruskal–Wallis tests. Anisometropes showed significantly reduced binocular function. Only 35.6% had normal fine stereopsis versus 86.0% of controls (p &lt; 0.001), and Titmus scores were worse (median 100 vs. 40 arcsec, p &lt; 0.001). Vertical PEP was higher in anisometropes (median 3 pixels, p &lt; 0.001), while horizontal PEP did not differ. Hyperopic anisometropia was most affected, with only 12.8% demonstrating normal fine stereopsis. Even with corrected BCVA, anisometropic patients—especially hyperopes—show persistent stereopsis and vertical alignment deficits. PEP and stereopsis assessments should be part of routine clinical evaluation and rehabilitation planning. Keywords: Anisometropia, Stereopsis, Binocular vision, Perceptual eye position, Amblyopia, Hyperopia, Titmus test

Geographic patterns in head morphology can reveal important aspects of population structure and phenotypic differentiation in marine species. We investigated these patterns in the broad-nosed pipefish Syngnathus typhle Linnaeus, 1758, a coastal species widely distributed across distinct marine regions (Baltic, North, East Atlantic, and Mediterranean seas). Using landmark-based geometric morphometrics, we quantified head morphology variation in 241 live, wild-caught adults. Analyses revealed consistent geographic patterns in snout elongation, head depth, and eye position. Multivariate comparisons showed significant morphological separation among marine regions, with high classification success based solely on head morphology. These results indicate that S. typhle populations are spatially structured and not morphologically homogeneous across their range. Our findings demonstrate the utility of geometric morphometrics to detect subtle geographic variation in morphologically conservative taxa such as pipefish and provide a quantitative baseline for future research on phenotypic diversity and conservation management. Importantly, the study is based on non-invasive monitoring protocols using live animals.

Distortion of perceived visual space after prolonged horizontal eccentric gaze holding.