Experts say screen-time rules are important, but so is honest conversation about the perks and pitfalls of a digital world.

Michelle Holden has a rule in her house. Her three kids, ages 7 to 12, get two hours of screen time per day: one hour before lunch and one hour after lunch. Come dinnertime, the devices get put away.

Holden, a Dublin resident, realized she needed to start setting boundaries once her son, Carter, 12, received an iPad for Christmas from her parents. “It was getting out of control,” she said.

Holden's experience is far from unique. As the plethora of digital devices proliferates, parents are increasingly managing their children's screen time on cellphones, tablets and computers.

Forty-two percent of children ages 0-8 have their own tablet, up from fewer than 1 percent in 2011, according to research by Common Sense, a nonprofit organization focused on safe technology and media. These same kids are using mobile devices more, too, at 48 minutes daily now vs. five in 2011.

Holden said she noticed her children, Carter, Cami, 10, and Calista, 7, tended to zone out without time limits. “They lose track of all time, and they're not answering you,” she said.

The American Academy of Pediatrics recommends no more than one to two hours of screen time per day, said Michael Flores, a clinical psychologist at Nationwide Children's Hospital.

If your household is above that threshold, consider establishing a screen time plan to set limits. Don't be discouraged if a plan takes a while to stick, Flores said. Progress can be slow—more than a week or two is required to get accustomed to new rules, he said. But clear limits, expectations and consistency will help make the transition easier.

As kids grow older, parents may have a tougher time monitoring them, Flores said. That's when trust becomes important. With teens older than 15, a contract with clear and consistent digital expectations tends to reduce the frequency of arguments, Flores said. “It keeps the parent accountable, too,” he said.

While Holden's kids aren't on social media, she knows the time is rapidly approaching when Carter will start using those platforms.

For Toby Carpenter, an eighth-grade science teacher at Dublin's Karrer Middle School, regular monitoring is part of the deal for her 13-year-old daughter Tatem's screen time privileges. Carpenter said she follows her daughter's Instagram account and regularly looks at her text messages.

A partnership with parents and teachers is important to mitigate social media's impact in the classroom, Carpenter said. In the days before social media, a conflict outside the classroom could easily be brought inside. That still holds true, even if the argument happened online.

While social media gives children a way to connect to their peers, it also has a darker side and leaves them vulnerable to cyberbullying and self-esteem problems, Flores said. Children get into the habit of checking their posts and may base their self-worth, in part, on the number of likes or positive responses they receive.

The distorted reality of social media posts and Instagram and Snapchat filters also can provide a false sense of perfection, and children and teens may feel insecure comparing themselves to others as a result, Flores said.

Like adults, children also are prone to technology addiction, because the stimulation and interaction impacts pleasure centers similarly to alcohol or drugs, said Sara Harrison-Mills, director of clinical operations with counseling provider Syntero. The ability to find things quickly online also gets kids used to instant gratification, she said.

Communicating with children about internet safety and risks such as identity theft, sexting, online grooming and cyberbullying is important, Mills said, as is discussing privacy limitations of the internet and social media. The old adage still applies: If you wouldn't want your grandparents to see it, don't post it.

When social media or screen time begins to affect a child's academics, sleep, health, behavior, social relationships or emotional well-being, parents should intervene, Flores said. A pediatrician, counselor or therapist can help if parents notice significant changes, he said.

Experts are divided on whether snooping on children's and teen's devices and online behavior is a good idea. Flores believes it's not. If a child finds out a parent is spying, he said, that will only encourage him to become more secretive. Instead, Flores recommends employing parental controls on devices and online platforms.

Setting a good example is also important, he said. “Parents are the first and the best teachers for their kids.”