Dry eye issues are on the rise in children, as is myopia; both have a link with increased screen time. This link is still being comprehensively explored, although meta-analyses indicate an association (Huang et al, 2015; Lanca and Saw, 2020). The impact of screens might be more related to duration and close working distance than to the screen itself, with every one diopter-hour of near work per week increasing myopia risk by 2% (Huang et al, 2015).

Most research on visual environment and refractive error development in children uses subjective surveys. Recently, smartphone data usage in children was measured as an objective indicator of time spent on the device and then was correlated to frequency of myopia (McCrann et al, 2021).

There were two notable findings. First, there was a significant relationship between increased data usage and myopia; the myopes used almost twice as much data per day as the non-myopes did. Second, when the smartphone-using children were subjectively surveyed on their device time, there was no significant difference reported between myopes and non-myopes. Ponder this: either the myopes are consistently using apps that gobble twice as much data as the non-myopes are (unlikely) or they are grossly underestimating their device time (much more likely). This indicates the immense value of objective measures to truly gauge the link between near work, screen time, and time spent outdoors in both myopia development and progression.

A Risk Factor

Smartphone usage is a significant risk factor for pediatric dry eye disease (DED). A Korean study that involved almost 1,000 children aged 6-to-11 years surveyed time spent on technology and evaluated dry eye signs with slit lamp examination and symptoms with the Ocular Surface Disease Index (OSDI) questionnaire. Diagnosis of DED was based on International Dry Eye Workshop classifications. Children living in both urban and rural areas were recruited to the study. The frequency of DED was 8% in urban and 3% in rural children and was 9% in older children (9-to-11 years) and 4% in younger children (6-to-8 years) (Moon et al, 2016).

Almost 2.5 more hours per day were spent on smartphones by children who have DED—an average of 0.6 hours and 3.2 hours per day in the non-DED and DED groups, respectively. There was also less time spent outdoors in the DED group —1.5 hours per day, compared to 2.3 hours in the non-DED children. Four weeks of smartphone cessation improved DED signs and symptoms. Interestingly, there was no relationship shown between total learning or television watching time and DED —the stronger correlation was with smartphone use (Moon et al, 2016).

What Can We Do in Practice?

To tackle screen time as a risk factor for both DED and myopia in children, we can advise school-aged children and their parents to:

• Reduce leisure screen time to two hours per day or less, according to the American Academy of Pediatrics (2021).
• Increase time spent outdoors to at least 90 minutes per day. With nine hours a week of time outdoors, a reduction of 50% in incident myopia was observed on meta-analysis (Xiong et al, 2017).

Dry eye is important in pediatric contact lens practice and especially in myopia management, in which being proactive means fitting more contact lenses to children (Bullimore and Richdale, 2020). Prescribing survey data show that children fit with contact lenses for myopia control are, on average, younger (13 years) and that 84% wear their lenses seven days a week, compared to an average age of 15 years and 56% full-time wear in non-myopia-control fits (Efron et al, 2020). Managing successful, long-term contact lens wear in children involves a multifaceted approach, with the ubiquity of screens presenting a burgeoning challenge. CLS

For references, please visit www.clspectrum.com/references and click on document #308.