The effect of fixation stability on stereopsis in school-age children

Fixation stability is the ability of the eyes to maintain a constant and stable gaze on the fixation target. One of the visual functions that can be affected by unstable fixation is stereopsis. Stereovision is important for a variety of daily tasks, as well as for using stereoscopic displays in visualizations and entertainment, such as watching movies and playing video games. The interaction between fixational stability and stereopsis in different conditions has often been studied in children with amblyopia. The aim of our research is to explore the relationships between binocular fixation stability and stereopsis in school-aged children who do not have amblyopia and strabismus in their anamnesis. The children were divided into two groups: those with normal stereoacuity (≤ 60 arcsec in the TNO test) and those with reduced stereoacuity (≥120 arcsec in the TNO test). The fixation target was demonstrated on a computer screen, and eye movements during fixation were recorded using a Tobii Pro Fusion eye tracker operating at 250 Hz. The results demonstrate that children with better stereoacuity tend to have more stable fixation compared to children with reduced stereoacuity. However, the difference in fixation stability was not significant.