The light emitted by electronic devices such as an iPad or iPhone can lead to sleepless nights.
Getting less sleep puts children at risk for poor grades and mood problems, according to Daniel Lewin, PhD, D'ABSM, a pediatric psychologist, sleep specialist, and licensed clinical psychologist at Children’s National Health System. Lewin is the Associate Director of Pediatric Sleep Medicine and Director of the Pulmonary Behavioral Medicine Program at Children’s National, and Assistant Professor of Pediatrics at George Washington University School of Medicine.
Dr. Lewin offers tips about using e-readers (or other similar devices) and their impact on sleeping. He discusses the connection between usage and sleep patterns among children and offers advice to parents about how to reduce the use of these devices at nighttime, which are common in many households.
Do tablets, e-readers harm sleep?
There are at least three reasons why tables and e-readers can result in delayed and disrupted sleep.
“The light from these devices can result in later fall asleep and times and shorter sleep. Light, even at these low levels resets a clock-like center of the brain and delays cascade biological processes that prepare us for sleep,” he said. This is particularly problematic for teens and young adults who have a biologically based tendency to go to bed later and wake up later.
Another reason is “high interest and high reward content directly competes with sleep as it keeps us engaged and hooked in.”
“It is easy to stay up later, lose track of time and prioritize high reward activity over sleep,” he said.
“When sleep onset is associated with the use of these devices (for example using the devices in bed or within a half hour of bedtime) and we have one of the dozen or more normal awakenings from sleep we may be inclined to turn on the device as a sleep re-initiation tool.”
“Finally, most of these devices make noises,” he said. Alarms, incoming Tweet, message and update alerts disrupt sleep.
What is the effect of light-emitting devices on the body?
When light enters the eyes and before it is processed by the visual cortex at the back of the brain, it passes through a small part of the brain that serves as a central biological clock. That clock coordinates sleep- wake states and many other critical functions of the body and brain.
“Depending on the time of day that we are exposed to light, this center of the brain can either initiate or shut down the sleep initiation process. Bright light in the morning will tend to advance the sleep period and bright light at night will delay the sleep period,” he said. “Dim light within an hour of bedtime actually helps with the sleep initiation process. In general, light plays a critical role in the regulation of circadian rhythms.”
Do these devices disrupt circadian rhythms?
Dr. Lewin said these devices affect the internal body clock that’s synchronized to light-dark cycles and other environmental cues including temperature.
“Circadian rhythms do not only involve sleep and wake states. In fact, there are clock genes in every cell in the body that appear to be dependent on sleep wake, feeding, social, and other behavior.
These clock genes probably contribute to sleep-wake regulation, but they are also involved in many other primary functions of cells and organ systems,” he said.
Keep all electronic devices out of bedrooms
He said if you can’t do this, significantly limit their use within an hour of a child’s bed time.
“Try it for a week and see if makes a difference,” he said. “Challenge your children to get their whole social network to try the same experiment together. That way no one feels like they are missing out on important communications. If these devices are going to be used at night, there is some evidence that blocking blue spectrum light may result in less of an impact on the circadian and sleep/wake regulation system.”
He said parents should also set an example by putting away their own devices when spending time with children.
“To improve overall sleep health, establish a regular sleep wake schedule that changes less than 30 minutes on weekdays,” Dr. Lewin said. “On weekends, fall asleep and sleep-in time should not differ from school nights more than 1.5 to 2 hours. Large shift in daily and sleep cycles has been called ‘social jetlag’ and can pose a significant problem for children in all age groups, but particularly teens.”
He also said, “School-age children should not need to take long naps during the day and if they have difficulty staying awake they may be getting insufficient sleep or may have a sleep disorders.”
Dr. Lewin discusses how more American children are getting less sleep, according to a new study published last week in Pediatrics, a publication of the American Academy of Pediatrics.