Screen Time and Developmental Eye Movement Testing in Middle School Students

Abstract

Background: Screen time continues to increase among children and youth, yet little is known about its potential effects on oculomotor development and function. The aims of the current study were to (a) compare oculomotor function in children today to those tested before smartphone use and (b) explore correlations between screen time use and oculomotor function among children today. Method: A retrospective comparison was conducted comparing normative data published in the Developmental Eye Movement (DEM) Test manual in 1990, prior to the invention of smart devices, to data collected in 2020. Correlations between screen time and DEM variables were also explored within the current sample. Results: Sixty middle school students reported spending on average 45.5 hours/week on screens with approximately 18.5 hours/week on iPhones, 14.5 hours/week on television and 10.5 hours/week on computers. Surprisingly, DEM performance was not significantly improved in the current sample compared to the historical sample. There were also no significant correlations between any screen time variables and oculomotor metrics within the current sample. Conclusion: Despite the significant increase in screen time usage since 1990, DEM performance was replicable among 6th, 7th, and 8th grader students tested 30 years later. A statistically significant difference was found among 7th graders on DEM Vertical, where the 2020 students performed slower however, this difference may not be clinically significant. Importantly, DEM Ratio, a key variable for identifying ocular motility dysfunction (OMD), was also not significantly different between 1990 and 2020. Moreover, screen time in the current sample did not correlate with any DEM variables. This study provides preliminary evidence indicating that as measured by the DEM Test, increased screen time may not affect ocular motility. Further research is warranted using more finite methods for measuring saccade and smooth pursuit eye movements during the use of screened devices.