Since Americans have embraced the smartphone as a burgeoning limb extension, apprehension about its ramifications have run amok—especially in the eye care community. But, according to researchers from Singapore, the ubiquitous screens we gaze upon can be acquitted of at least one charge—an association with myopia.

The investigators point out that, yes, digital screen time is frequently cited as a potential modifiable environmental risk factor for myopia. But, they say, this association is not consistent. For starters, myopia prevalence was already on the rise before digital devices really took off in some countries. So, the team looked through 15 studies that included a total of 49,789 children between the ages of three and 19. Seven studies found an association between screen time and myopia. Five found no association.

The purpose of this review and meta-analysis was to summarize the available relevant evidence, the researchers said in their paper. They found no clear association between screen time and myopia prevalence, incidence or myopia progression. This is one of the first systematic reviews to comprehensively summarize existing data on screen time in children and myopia.

They add that a particular nuance of the study is that screen time may lead to reduced time outdoors, which is associated with elevated myopia, whether that time indoors is spent looking at screens or reading books. No data exists, however, on whether that indoor time is actually associated with digital device use either. But they’re not ready to call it a day yet, especially as smartphones continue to dominate ever-greater chunks of our time. “Given the rise in hours spent by children using screens, further studies are warranted using objective screen time measurements,” the report reads. 

Lanca C, Saw S. The association between digital screen time and myopia: a systemic review. Ophthal Physl Opt. January 13, 2020. [Epub ahead of print].