Assessment of Refractive Status and Vision-Related Behaviors in First Grade Schoolchildren: A Comparative Study

Abstract

Relevance: This study explores weekday and weekend visual behaviors in first-grade children, a critical period for refractive development. By linking refractive status with screen exposure, near work, socioeconomic factors, and outdoor activity, it highlights modifiable habits that may guide early myopia prevention strategies.  

Purpose: To investigate the relationship between vision-intensive behaviors and refractive status in first-grade primary school students across weekday and weekend patterns. 

Methods: A total of 318 first-grade schoolchildren (318 eyes, one per child) were classified as three groups on refractive status. Demographic characteristics and parent-reported duration of behaviors per day (screen use, reading, outdoor activity, etc.) were compared across groups defined as myopic (≤−0.50 D), emmetropic (−0.50 D to +0.50 D), and hypermetropic (>+0.50D) on weekdays and weekends. The Kruskal-Wallis test, Dunn’s test with Bonferroni correction and Spearman correlation were used for statistical analysis.

Results: The study consisted of myopic (n=35; 11.0%), emmetropic (n=205; 64.4%), and hypermetropic participants (n=78; 24.5%). Myopic children came from families with a significantly lower socioeconomic status and received screen-time restriction less often than the other groups (p<0.05). Average weekday total screen time was 179.2±168.7 min for myopic, 187.1±132.0 min for emmetropic, and 161.4±130.6 min for hypermetropic children. On weekends, emmetropic children had the longest total screen time (278.6±195.2 min), exceeding both myopic (p=0.037) and hypermetropic (p=0.001) peers. Mean weekend combined near work was longest among emmetropic children (474.3±263.8 min), significantly higher than hypermetropic children (392.8±214.9 min; p=0.003). Crucially, myopic children spent significantly less time outdoors during weekends (p<0.05).

Conclusions: Myopia was associated with lower socioeconomic status and insufficient weekend outdoor activity. High screen time and total near work were observed in emmetropic children, suggesting a potential future risk. In this age range where myopia typically begins, these findings emphasize that early behavioral guidance should promote outdoor play and moderate extended screen exposure, to reduce risk of myopia occurrence and progression.