The association between time spent on screens and reading with myopia, premyopia and ocular biometric and anthropometric measures in 6‐ to 7‐year‐old schoolchildren in Ireland

Abstract

More time spent on near tasks has consistently been associated with the promotion of myopia. The World Health Organization advises limiting daily screentime to less than 2 h for children aged five and over. This study explored the relationship between time spent on screens and reading/writing with refractive status, ocular biometric and anthropometric factors in 6-to 7-year-olds in Ireland. Methods: Participants were 723 schoolchildren (377 boys [51.8%]), mean age 7.08 (0.45) years. The examination included cycloplegic autorefraction (1% cyclopentolate hydrochloride), ocular biometry (Zeiss IOLMaster), height (cm) and weight (kg). Screentime and reading/writing time were reported by parents/legal guardians by questionnaire. Myopia (≤−0.50D) and premyopia (>−0.50D ≤ 0.75D) risk assessments were performed using logistic regression, and multivariate linear regression was used to analyse continuous variables. Results: Reported daily screentimes were 31% <1 h, 49.5% 1-2 h, 15.6% 2-4 h and 3.9% >4 h. Reading/writing times were 42.2% frequently, 48.0% infrequently and 9.8% seldom/never. Linear regression, controlling for age and ethnicity, revealed >2 h/day on screens was associated with a more myopic spherical equivalent [β = −1.15 (95% confidence intervals {CIs}: 1.62-0.69, p < 0.001)], increased refractive astigmatism (β = 0.29, CI: 0.06-0.51, p = 0.01), shorter corneal radius (β = 0.12, CI: 0.02-0.22, p = 0.02), higher axial length/corneal radius (β = 0.06, CI: 0.03-0.09, p < 0.001), heavier weight (β = 1.60, CI: 0.76-2.45, p < 0.001) and higher body mass index (BMI) (β = 1.10, CI: 0.28-1.12, p < 0.001). Logistic regression, controlling for age and ethnicity, revealed daily screentime >2 h was associated with myopia (OR = 10.9, CI: 4.4-27.2, p = 0.01) and premyopia (OR = 2.4, CI: 1.5-3.7, p < 0.001). Frequent reading/writing was associated with screentime ≤2 h/day (OR = 3.2, CI: 1.8-5.8, p < 0.001). Conclusion: Increased screentime was associated with a more myopic refraction, higher axial length/corneal radius ratio, increased odds of myopia, premyopia, higher degrees of astigmatism, increased weight, BMI and decreased reading/writing time. Dedicated education programmes promoting decreased screentime in children are vital to prevent myopia and support eye and general health.

Subjective behavioral measures in myopic and pre-myopic children before and after the COVID lockdown

“…Therefore, it is important to consider the timing of data collection when comparing results from different studies. Although our results show that Spanish children after lockdown changed their habits by increasing time outdoors and decreasing the time for near vision activities and the use of electronic devices, some studies have reported an increased screen time and a decreased outdoor time among children during periods of strict COVID-19 regulations in other regions of the world ( 30–32 ). A recent systematic review ( 14 ) of the effects of remote learning during the COVID-19 lockdown on children’s visual health showed that most of the studies revealed a decline in visual health among children who were exposed to virtual learning strategies during the COVID-19 lockdown.…”

“…Our results show that after the COVID lockdown, more than 50% of the children spent between 1.6 and 2.7 h per day outdoors. According to the latest meta-analysis, spending more time outdoors can slow down the change of axial length and decrease the risk of myopia (27); for each additional hour spent outdoors per week, the risk of developing myopia decreased by 2% (28) and the risk ratio for high versus low outdoor time was 0.54 to 0.57 in clinical trials and longitudinal cohort studies (29). In this sense, it would be convenient to explain to the families of children who are pre-myopic that they spend more time outdoors as a protection factor.…”

“…The difference in results may be due to the difference in the average age of the studied children; our study included younger children (myopic: 6.25+/−0.77, pre-myopic: 6.11+/−0.79, hyperopic: 6.13+/−0.79). Children between 6 and 7 years of age are less likely to have unsupervised access to screen-based technologies ( 30 ) and spend more time outdoors and less time on near-work activities. Another possible reason for the differences in results could be that the questionnaires were administered at different periods after the COVID-19 pandemic in both studies.…”

Shifting landscapes: The environmental impact of urbanisation on childhood myopia, obesity and diabetes

“…For example, screen time has eclipsed reading/writing time for Irish 6-to 7-year-olds. 7 The National Sleep Foundation reported virtually all Americans have a screen in their bedroom and use it within an hour of bedtime. 8 Global sleep patterns indicate that average sleep duration is decreasing.…”

“…The ubiquitous adoption of handheld digital devices and screen media following the 2007 launch of the Apple iPhone (http://apple.com) has increased our exposure to blue‐rich white light from screens and digital devices in the evening and at night, disrupting our body's natural sleep cycle. For example, screen time has eclipsed reading/writing time for Irish 6‐ to 7‐year‐olds 7 . The National Sleep Foundation reported virtually all Americans have a screen in their bedroom and use it within an hour of bedtime 8 .…”