Does My Child's Tablet Before Bed Really Ruin Their Sleep? What the Research Says

It’s 9pm, the lights are dim, and the one thing that will actually get your child to lie still is the tablet. You know you’re probably not supposed to let it happen, but it works, and the guilt creeps in anyway.

The Study That Started the Worry

Much of today’s “no screens before bed” advice traces back to a study by Anne-Marie Chang, Daniel Aeschbach, Jeanne Duffy, and Charles Czeisler, published in the Proceedings of the National Academy of Sciences in late 2014. They had 12 adults read either a printed book or a light-emitting e-reader for about four hours each evening, across several nights. The e-reader suppressed melatonin — the hormone that signals “it’s time to sleep” — by roughly 55%, compared to no suppression at all with the printed book, and it pushed back participants’ natural sleep onset by well over an hour.

That’s a real, striking result. It’s also a study of 12 grown adults reading in a sleep lab, not a houseful of children watching cartoons on a phone — worth knowing before treating it as the final word on your own child’s bedtime.

What the Research on Actual Kids Shows

For children specifically, the clearest picture comes from a 2015 review by Lauren Hale and Stanford Guan in Sleep Medicine Reviews, which pulled together dozens of studies on school-aged children and adolescents. The pattern held up consistently: more screen time, especially closer to bedtime, was associated with shorter sleep duration and worse sleep quality. But — and this matters — almost all of this evidence is observational. It tells us screens and poor sleep travel together; it can’t fully separate how much is the light itself, how much is the stimulating content, and how much is simply that screen time quietly eats into the wind-down time a bedtime routine used to occupy.

Where It’s Genuinely Unclear

So is it the blue light, specifically? Possibly part of it — but a child scrolling a fast-paced video right before lights-out would likely sleep worse even on a non-light-emitting device, just from the mental stimulation and the delayed bedtime it causes. Nobody has cleanly isolated “light” from “content” from “later bedtime” in children the way the 2014 study did for adults. The honest answer is that screens before bed are associated with worse sleep in kids, for reasons that are probably a mix of all three, not one tidy mechanism.

What This Means Tonight

• Swap the last 15–20 minutes before lights-out for a printed book, read either by your child or to them. It sidesteps the light question entirely and still slows things down.
• If the tablet has to be part of the routine, end it a little earlier rather than right up to lights-out.
• Keep the overhead lights dim rather than off — a softly lit room doesn’t need daylight-level brightness to be comfortable for reading.
• Don’t overhaul the whole routine overnight. Shifting the screen even 15 minutes earlier is a real, doable change — not an all-or-nothing swap.

Related Reading

• My 2-Year-Old Won’t Put Down My Phone — What Actually Helps
• My Child Only Reads on a Screen — Does That Still Count as Reading?
• Does Screen Time Really Hurt Children’s Attention Span? What the Research Actually Shows

Find books that fit your 8-year-old — take the 2-minute reading assessment

Sources

• Chang AM, Aeschbach D, Duffy JF, Czeisler CA. “Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness.” Proceedings of the National Academy of Sciences, 2015 (published online December 2014).
• Hale L, Guan S. “Screen time and sleep among school-aged children and adolescents: A systematic literature review.” Sleep Medicine Reviews, 2015.