This research examined risk factors associated with myopia (near-sightedness) in schoolchildren in Ireland and compared the findings to previous studies. Myopia is a growing health issue in many countries, including Ireland. According to the recent report, one in five children (age 12-13) in Ireland are affected by myopia. If efforts to reduce myopia-related visual impairments are to be effective, they need to be guided by an understanding of both the extent of the problem and factors associated with the problem. This is an issue the current study addressed.
Thirty-seven schools participated in this study. Stratified random sampling was used in selecting the schools. This form of sampling is used to guarantee that the research sample (i.e., the individuals or groups being studied) represents specific sub-groups, which in this case included socially disadvantaged/non-disadvantaged status, urban/rural status, and primary/postprimary educational status. Data was collected on 1626 children drawn from the participating schools -- 728 children (age 6-7) from primary schools and 898 (age 12-13) from postprimary schools. The data for each participating child included vision test (cyclopleged autorefraction) results, height and weight measurements, daily screen time use, and daylight exposure.
Results showed a significantly higher prevalence of myopia in children aged 12–13 than in children age 6-7 and in children of non-white ethnicity. Myopia was also significantly higher in children who (a) used screens more than three hours a day, (b) were obese, (c) had a sedentary lifestyle, (d) engaged frequently in reading/writing, (d) had less daylight exposure during summer time, (e) were born in the spring season, (f) had a paternal history of myopia, and (g) bottle fed for the first three months of life. There was little difference in the prevalence of myopia between children living in urban and rural areas of Ireland and in children from different socioeconomic backgrounds.
Many of the findings from this study are consistent with previous research, including the positive association between decreased risk of myopia and time outdoors. An interesting facet of the current study is the comparison of winter and summer time outdoors in relation to myopia in children. While myopia prevalence was higher in children spending less than two hours per day outdoors during summer time, winter daylight exposure was not significantly associated with myopia. This may suggest that bright sunlight versus just time outdoors provides some measure of protection from myopia. A clear take-away message from this research, however, is that public health education programs addressing the importance of daily outdoor activities may be beneficial to the eye health of children in Ireland. More research – especially longitudinal research – is needed to further investigate demographic and lifestyle risk factors associated with myopia in children.
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