How Screen Time Affects Sleep for Infants Through Preschoolers

A new study finds that preschoolers and toddlers who log regular daily screen time get less sleep, take longer to fall asleep, and go to bed later.

A toddler using an iPad in the pitch dark.
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Whether it's a few minutes of educational programming during dinner prep or interactive games to stave off cabin fever, screen time has never been so compelling for young children — even babies are now “using” tech. But when it comes to sleep, what’s the impact? Read on for the rundown.

How watching screens affects very young children

The American Academy of Pediatrics (AAP) recommends that babies and young children avoid exposure to all screens, other than video chats, until they’re 18 to 24 months old.

The reality, though, is that many babies and toddlers have regular screen exposure. One study, by Common Sense Media, found that the under-2 set spends an average of 49 minutes a day using screens, and a third of them watch TV or videos every day.

Due, perhaps, to the taboo nature of screen time for such young children, this age group hasn’t been studied as extensively as older kids and teens, but a recent study found that screen exposure in babies as young as 3 months affects their sleep.

Interestingly, for 3-month-olds, daytime screen exposure was associated with less daytime sleep, along with longer nighttime sleep and fewer middle-of-the-night wakings.

From the parent’s perspective, this may seem to be a benefit, acknowledges Michal Kahn, Ph.D., a clinical psychologist and lead author of the study. However, she says, “it may not be a good idea to deprive infants of daytime sleep using screens when they are clearly fatigued and sleepy, given the importance of sleep to their development.”

Toddlers, preschoolers, and screens

As kids grow, so does their media use. Though the AAP recommends that screen use be limited to one hour a day for kids ages 2 to 5, the Common Sense Media study showed that 2- to 4-year-olds logged two-and-a-half hours of overall daily screen use, with TV and videos accounting for 80% of this.

About half of the parents surveyed said their kids’ screen time allowed them to get things done. Additionally, most parents saw their kids’ screen use as educational, and more than half thought it helped their kids’ creativity.

When it comes to sleep, though, this screen time often comes at a cost. A meta-analysis of 20 previous studies found that toddlers and preschoolers who logged more daily screen time generally got less sleep, took longer to fall asleep, and also tended to go to bed later.

In another study, focused on 13-month-olds, Kahn found that every minute of daytime touchscreen use resulted in one minute of lost nighttime sleep. This was likely due to the blue light exposure from the proximity of the screens, she says, as well as the stimulation from youngsters’ engagement with the content, given that toddlers are already able to scroll by this age.

Although increased screen exposure generally has greater effects, the impact also varies by tech type. For TV watching, for example, one study found the tipping point for preschoolers was one hour a day. With each additional hour beyond that, the risk for sleep disorders increased by 12%.

Another study, which focused on portable electronic devices, found that each additional hour of use beyond the recommended one-hour daily limit for preschoolers was associated with up to 11 minutes less sleep.

How blue light exposure affects kids

One contributing factor to kids’ sleep loss is the blue light that back-lit devices emit, which boosts alertness. Although this is true for all ages, the effects of light exposure are even greater for young kids, whose eyes are more sensitive to light. That’s likely because their eyes have larger pupils and clearer lenses.

In fact, researchers who have studied the effect of light found that when preschoolers were exposed to bright light during the hour before bed, their levels of melatonin, the hormone that prompts feelings of sleepiness, were dramatically reduced. Perhaps due to that increased eye sensitivity, even dim light exposure greatly suppressed melatonin.

How screen time affects behavior and sleep

Screen time can also contribute to behavior issues, including tantrums, trouble paying attention, and impulsivity. When Kahn studied 3- to 6-year-olds, she found that those who spent more time using screens had worse behavior — but only when they were sleep-deprived.

Screen time was specifically linked to behavior issues when kids averaged less than 9.94 hours of sleep a night. That’s only about three-and-a-half minutes under the minimum recommended amount for preschoolers, which is 10-13 hours of nightly sleep, underscoring that it doesn’t take much shortfall before the effects of sleep deprivation kick in.

Meanwhile, for the preschoolers who weren’t sleep-deprived, screen use didn’t have the same negative impact.

For this age group, more screen time “is only associated with more problems when the child doesn’t get enough sleep,” Kahn says. “We are used to thinking that screen time is simply ‘bad,’ but reality is far more nuanced.”

Advice for parents

The effects of screen time on young kids’ behavior and on their sleep are interrelated with other factors. Moreover, it’s not just total time on screens that matters.

In addition to limiting screen time, the AAP recommends that parents monitor content, watch or participate together, and power down screens or devices one hour before bedtime. Work with the child to establish reasonable boundaries. For some kids, this could mean letting them set an egg timer for their screen time or having them prompt a voice-assisted device to set a timer.

Another key recommendation: Keep devices out of young kids’ bedrooms, given that their mere presence has been associated with shorter sleep times. Consistent bedtimes and bedtime routines help, too.

Avoid associating screens with rewards, as this association can lead to increased focus on and use of screens.

Finally, some kids may be more affected by tech than others; if this is the case, parents may want to set additional screen time limits.