Uncorrected refractive error and unsatisfactory performance on several clinical accommodation and binocular vision tests are more common in children who struggle with reading. The aim of the current study is to explore the prevalence of accommodative and binocular dysfunctions in children with and without reading difficulties. Reading performance was assessed with the Acadience Reading (formerly DIBELS Next) test adjusted and validated for the Latvian language. Children with (N = 39) and without (N = 43) reading difficulties underwent thorough assessment of their subjective refraction, as well as binocular and accommodation functions. The results demonstrate no difference in the prevalence of complaints between children with and without reading difficulties (26% and 23%, respectively). However, children with reading difficulties more frequently present with significant uncorrected refractive errors and/or accommodative and binocular dysfunctions than children without reading difficulties (69% and 47%, respectively). According to the findings, even in cases where a child does not exhibit any ocular or visual complaints, a comprehensive visual function evaluation should be required for any child who struggles with reading.

Children with dyslexia have previously been demonstrated to perform more corrective saccades in sequential non-reading saccade tasks, having trouble with maintaining a stable fixation, as well as reduced performance in smooth pursuit tasks. The current study aims to provide a comprehensive analysis of different eye movements (saccades, smooth pursuit eye movements and fixation stability) in children with and without reading difficulties who were tested by a validated reading performance test applied in the school environment. Altogether, 377 children (6–13 years old; 182 boys and 196 girls) were voluntarily involved in the study. Reading performance was determined by the Acadience^® Reading literacy assessment tool. The Tobii Pro Fusion Eye-tracker was applied to determine oculomotor performance in children with and without reading difficulties. The results of saccadic eye movement, smooth pursuit eye movement, and fixation stability in a non-reading task did not reveal a statistically significant difference in oculomotor performance in children with and without reading difficulties. The results of the current study indicate that the oculomotor system in children with reading difficulties (not excluding dyslexia) is intact. The results propose that the observed differences with previous studies exploring eye movements in dyslexic children might be attributed to the participant selection.

(1) Background: Saccadic eye movements are rapid eye movements aimed to position the object image on the central retina, ensuring high-resolution data sampling across the visual field. Although saccadic eye movements are studied extensively, different experimental settings applied across different studies have left an open question of whether and how stimulus parameters can affect the saccadic performance. The current study aims to explore the effect of stimulus contrast and spatial position on saccadic eye movement latency, peak velocity and accuracy measurements. (2) Methods: Saccadic eye movement targets of different contrast levels were presented at four different spatial positions. The eye movements were recorded with a Tobii Pro Fusion video-oculograph (250 Hz). (3) Results: The results demonstrate a significant effect of stimulus spatial position on the latency and peak velocity measurements at a medium grey background, 30 cd/m² (negative and positive stimulus polarity), light grey background, 90 cd/m² (negative polarity), and black background, 3 cd/m² (positive polarity). A significant effect of the stimulus spatial position was observed on the accuracy measurements when the saccadic eye movement stimuli were presented on a medium grey background (negative polarity) and on a black background. No significant effect of stimulus contrast was observed on the peak velocity measurements under all conditions. A significant stimulus contrast effect on latency and accuracy was observed only on a light grey background. (4) Conclusions: The best saccadic eye movement performance (lowest latency, highest peak velocity and accuracy measurements) can be observed when the saccades are oriented to the right and left from the central fixation point. Furthermore, when presenting the stimulus on a light grey background, a very low contrast stimuli should be considered carefully.

The aim of the study was to analyze the stability of dominant and non-dominant eye fixations, as well as the influence of development on fixation stability. The study analyzed fixation stability in 280 school-age children, ranging in age from 7 to 12 years old. Fixation stability was determined by calculating the bivariate contour ellipse area (BCEA). During the fixation task, eye movements were recorded using the Tobii Pro Fusion eye tracking device at a 250 Hz sampling frequency. The results indicate that the fixation stability of dominant and non-dominant eyes, as well as the fixation stability of each eye regardless of dominance, improves as children grow older. It was found that for 7 and 8-year-old children, fixation in the dominant eye is significantly more stable than in the non-dominant eye, while in older children, there is no significant difference in fixation stability between the dominant and non-dominant eye.

The aim of the study was to determine the normative data of the computerized DEM test for school-age children in Latvia. The study analyzed data on the performance (test execution time, duration, number of fixations, and number of errors) of 291 children while completing the computerized DEM test. Eye movement fixations were recorded with a Tobii Pro Fusion video-oculograph (250 Hz). According to the results of the study, the performance of the computerized DEM test is 77 %. For the study, 1 SD (one standard deviation) was chosen as a criterion for determining test norms. In the study, the norms of the computerized DEM test in Latvia were developed in class groups—from 1st to 6th grade (aged 7 to 12 years), the results were summarized in a table as the minimum performance values of the computerized DEM test.

Biological motion perception is a specific type of perceptual organization, during which a clear image of a moving human body is perceptually generated in virtue of certain core light dots representing the major joint movements. While the processes of biological motion perception have been studied extensively for almost a century, there is still a debate on whether biological motion task performance can be equally precise across all visual field or is central visual field specified for biological motion perception. The current study explores the processes of biological motion perception and figure–ground segmentation in the central and peripheral visual field, expanding the understanding of perceptual organization across different eccentricities. The method involved three different tasks of visual grouping: (1) a static visual grouping task, (2) a dynamic visual grouping task, and (3) a biological motion detection task. The stimuli in (1) and (2) were generated from 12–13 dots grouped by proximity and common fate, and, in (3), light dots representing human motion. All stimuli were embedded in static or dynamics visual noise and the threshold value for the number of noise dots in which the elements could still be grouped by proximity and/or common fate was determined. The results demonstrate that biological motion can be differentiated from the scrambled set of moving dots in a more intensive visual noise than static and dynamic visual grouping tasks. Furthermore, in all three visual tasks (static and dynamic grouping, and biological motion detection) the performance was significantly worse in the periphery than in the central visual field, and object magnification could not compensate for the reduced performance in any of the three grouping tasks. The preliminary results of nine participants indicate that (a) human motion perception involves specific perceptual processes, providing the high-accuracy perception of the human body and (b) the processes of figure–ground segmentation are governed by the bottom-up processes and the best performance can be achieved only when the object is demonstrated in the central visual field.