Kids’ prolonged smartphone use could trigger dry eye

Putting smartphones away in favor of quality outdoor time may help alleviate pediatric dry eye symptoms potentially aggravated by long-duration device usage.

Published in the journal BMC Ophthalmology, the Korean study found not only that prolonged smartphone use was linked to pediatric dry eye disease, but also that outdoor activity seemed to hedge against the ocular surface disorder. In fact, children with dry eye symptoms who went four weeks without a smartphone actually showed subjective and objective signs of improvement.  

Researchers tracked 916 children, varying in age from 7 to 12 years, from urban and rural settings, through a series of assessments, generating a modified ocular surface disease index score for each child. Dry eye disease was identified in 6.6% of children. Of those, 97% reported using smartphones on average for more than 3 hours daily. Of the children without any dry eye symptoms, 55% used smartphones for an average of only 37 minutes daily.  

Moreover, those children with dry eye disease were less likely to venture outside—1.5 hours daily versus the children without symptoms, who averaged 2.3 hours daily. It also identified older, urban children (those in 4th through 6th grade) as most at risk for dry eye disease.

"Smartphone use in children was strongly associated with pediatric dry eye disease; however, outdoor activity appeared to be protective against pediatric dry eye disease," the study concludes.  

So what's causing this link?  

Researchers postulate that a reduced blink rate during prolonged smartphone usage causes faster evaporation of the lubricating tear film, citing a separate study that found computer screen use versus reading reduced the blink rate to only 5-6 blinks per minute.  

Prolonged device use influences blink patterns in other ways, as well. Yet another study found that subjects had significantly higher rates of incomplete blinks—i.e., the upper eyelid failing to contact the lower lid—when viewing a computer screen versus a book. This incomplete blink failed to adequately spread the tear film across the ocular surface in some cases. So, too, it's been proposed that a closer viewing distance, such as a small smartphone screen, can increase eye strain and fatigue.  

Pediatric eye care  

Ida Chung, O.D., AOA InfantSEE^® and Children's Vision Committee member, says this study underscores the importance of routine, in-person comprehensive eye examinations for children, especially given the findings related to smartphone use. While this Korean study found up to 65% of children are using digital devices routinely, a recent study in the journal Pediatrics found 97% of American children under the age of 4 use mobile devices regardless of family income.  

"Children with dry eye disease may be underdiagnosed," Dr. Chung notes, reviewing the study. "I agree with the authors' conclusion that dry eye disease must be detected early and should be treated with appropriate intervention and education. The best way to ensure this happens is to have parents think about their children's eyes and bring them to their doctor of optometry for a comprehensive eye examination."  

Technology in the form of computer screens and smartphones now is a ubiquitous part of life. The average American worker spends seven hours a day on the computer either in the office or working from home, while the average Millennial spends a whopping nine hours daily on devices, according to the AOA's 2016 American Eye-Q^® survey. Although 88% of surveyed Americans know that digital devices can negatively affect vision, not all know where to turn for help.  

To help alleviate digital eye strain, individuals should follow the 20-20-20 rule. In other words, take a 20-second break to view something 20 feet away every 20 minutes.

Find a helpful digital eye strain infographic.