Oculomotor Dysfunctions in Nonreading Tasks in Children With Dyslexia: Saccadic and Optokinetic Findings

ABSTRACT Background Dyslexia has been associated with atypical eye–movement control, but whether such differences arise only during reading or reflect broader oculomotor control remains debated. Methods We compared 40 children with dyslexia and 40 age/sex matched controls (8–12 years). Binocular eye movements were recorded with infrared video‐oculography (VOG) using a clinical VNG platform's oculomotor module. Participants performed a random‐step horizontal saccade task (targets at ±15° and ±20° from midline (step amplitudes 5°–40°); pseudo‐random 3–4 s intervals). Saccades were detected with manufacturer thresholds (40°/s, 800°/s 2 ). Primary outcomes were peak velocity (°/s), accuracy (%) and latency (ms); optokinetic responses (OKR) were analysed for each eye, and we report the interocular OKR difference (%). Trials with blinks/track‐loss were excluded a priori. Results Compared with controls, children with dyslexia showed slower saccades (307.5°/s vs. 453.5°/s), lower accuracy (71.5% vs. 98.5%) and longer latency (260.0 vs. 131.5 ms), all p < 0.001. Right‐eye OKR was reduced, whereas left‐eye OKR did not differ significantly, and the interocular OKR difference was significantly larger in dyslexia. These group differences remained significant after adjustment for relevant socio‐demographic covariates. Conclusions Children with dyslexia exhibited robust oculomotor differences during a nonreading task, consistent with altered visually guided saccade control. These results are associative rather than causal and suggest that oculomotor measures may provide complementary insight into dyslexia.