Development of Central and Peripheral Vision and Visual Field Asymmetries from Preschoolers to Adults.

This study explored how meridian, eccentricity, contrast, and age influence the development of central and peripheral visual acuity (VA) in 37 children (aged 4-12)-divided into three groups-and eight adults. Psychophysical methods were used to measure VA using Lea symbols at contrast levels of 40% and 80%, measured at the fovea and at eccentricities of 2°, 4°, 6°, and 8° along the superior, inferior, right, and left meridians. The results showed that children aged 6 to <8 years had already achieved adult-like VA performance at both central and peripheral locations across contrast levels. At 40% contrast, younger children (4 to <6 years) showed significantly lower VA, especially at the fovea and across eccentricities. The analyses revealed better VA along the horizontal meridian relative to the vertical meridian, and superior meridian performance relative to the inferior meridian, with these asymmetries becoming more pronounced with age. Although the results indicated significant differences between the right and left meridians, post-hoc analyses identified such differences only in a few conditions. Overall, the findings demonstrate that the development of VA is influenced by the interaction of meridional orientation, eccentricity, contrast, and age, highlighting an age-related increase in visual field asymmetry.