When does screen time become ‘too much’ for kids? Merced professor weighs in
AI-generated summary reviewed by our newsroom.
- Children average 7.5 hours of daily screen time, surpassing healthy limits.
- Heavy screen use links to sleep loss, eye strain, reduced focus, and anxiety.
- Experts recommend cutting screens an hour before bed to improve sleep quality.
Televisions, cellphones, iPads, computers. Screens on electronic devices have played an increasingly larger role in many people’s lives. But according to experts, there is no universal number to how much time children should spend daily using an electronic device.
Children from the age of 8 to 18 spend roughly 7½ hours per day watching a screen, according to the American Academy of Child and Adolescent Psychiatry.
Heather Bortfeld, professor of developmental psychology at UC Merced said more than four hours per day is considered high or heavy use for children.
Children are using screens and smart phones as a form of self-medication, a fun release, for social connection, and to fill their time when they lack alternative outlets, according to Bortfeld. The gratification from smartphone and screen use is instant, raising the brain’s dopamine levels, but the use can become problematic just as quick.
“It’s a coping mechanism, I would say,” Bortfeld said.
According to the Centers for Disease Control, teenagers with four or more hours of daily screen time reported higher levels of depression or anxiety than their peers.
When it comes to too much screen time, Bortfeld says sleep is the first casualty especially when screens are used within an hour of bedtime.
The light emitted from a phone’s screen is highly stimulating and interferes with the body’s ability to wind down, Bortfeld said. However, there are effective ways to mitigate this screen time casualty.
“What seems to work, interventions that limit screen use with young kids an hour before bed, seem to have positive outcomes,” she said.
Myopia, near-sightedness, is another problem that has been linked to too much screen time. A 2025 study found just one additional hour of screen time per day increased the odds of myopia.
“So, if you’re not using your long distance vision by getting out and looking on the horizon, by playing ball, or whatever it is you’re going to do outside, then your eyes are not going to develop the muscles to control the lenses that will allow for uncorrected vision,” she said.
When a child’s screen time hits the high to extreme range, attention spans and academic performance suffer, according to Bortfeld.
Bortfeld says there are warning signs to look for that indicate when a child has spent too much time in front of a screen including: inability to stay awake in class, mood changes, such as irritability when they don’t have access to screens, lying about using an electronic device, escalating conflicts over device use, and sneaking in use late at night.
“If they are showing withdrawal, it’s an addiction,” Bortfeld said. “It’s just like any other dopamine based addiction.”
This story was originally published September 22, 2025 at 5:03 PM.