Longitudinal Study in Japan Measures Parental Concern Related to Children's Eyesight and Television-Watching

Article: High levels of television exposure affect visual acuity in children
Source: Okayama University (Japan), via EyeWire News
Published: May 18, 2021

Two researchers published a large nationwide population-based longitudinal study in Japan assessing parental concern about their children's visual acuity as related to the amount of time the children spent watching television. The study used a national Japanese database (Longitudinal Survey of Newborns in the Twenty-First Century) of more than 47,000 children born between two time periods (January 10 to 17, 2001 or July 10 to 17, 2001). These children were surveyed annually between 1.5 to 5.5 years of age regarding daily duration of television- and video-watching, and followed in the second half of the study with annual surveys from ages 7 to 12 regarding parental concerns about their children's visual acuity. The investigators report, "Longer daily duration of television-watching at 2.5 years was significantly associated with concerns for the child’s decreased visual acuity between the ages of 7 and 12 years, but not at the ages of 3.5, 4.5, and 5.5 years." This association remained significant among the more than 28,000 children whose parents completed the survey in all six years. It is relevant to note that objective measures of visual acuity were not reported in this study. Nevertheless, the article states, "Parents have a close eye on their child’s visual development from an early age and any concern over a child’s eyesight is an accurate indicator of its visual health," and further explains that children in Japan undergo annual eye exams at school after age 6, which are graded from A through D, and that parental concern is closely related to this assessment. Interestingly, but not surprisingly, as a child’s age increased, the parent’s concern during later years decreased. Although there are clearly subjective and indirect connections between the research methods and the suggested conclusions that limit the study's design from fully extending beyond anecdotal evidence (as intended), this study nonetheless involved a large sample size and thus strongly reflects the cultural values and respect for parents in the study population. Because there does seem to be differences between ages 2.5 and 3.5 and between 1 and 2 hours of daily television exposure, future studies that include objective measures could elaborate on these findings.

My rating of this study: ⭐⭐🌸

Matsuo T and Yorifuji T. "Television-watching in the early years of life and the association with parents’ concerns about decreased visual acuity in their elementary school-aged child: results of a nationwide population-based longitudinal survey of Japan." Japanese Journal of Ophthalmology.  65:561–568. 16 March 2021. https://doi.org/10.1007/s10384-021-00831-x