Take a look around you and, in cars, shopping centres and restaurants, chances are you'll find young children engrossed, not in the world around them, but in their new digital reality.

Millions have smartphones and tablet computers gripped in their sweaty embrace, adopting the new internet-enabled technology as the standard operating platform for their lives, at work, home and play.

But it is not only adults who are on the iWay to permanent connection. As parents readily testify, many children don't just use the devices, they are consumed by them.

"These devices have an almost obsessive pull towards them," says Larry Rosen, professor of psychology at California State University and author of iDisorder: Understanding Our Obsession with Technology and Overcoming its Hold on Us.

"How can you expect the world to compete with something like an iPad3 with a high-definition screen, clear video and lots of interactivity? How can anything compete with that? There's certainly no toy that can.

"Even old people like me can't stop themselves from tapping their pocket to make sure their iPhone is there. Imagine a teenager, even a pre-teen, who's grown up with these devices attached at the hip 24/7 and you end up with what I think is a problem."

The technology has been absorbed so comprehensively that the jury on the potential impact on young people is not just out, it's yet to be empanelled.

"The million-dollar question is whether there are risks in the transfer of real time to online time and the answer is that we just don't know," says Andrew Campbell, a child and adolescent psychologist.

Media convergence means that everything from War and Peace, television, movies, video, computer games and the internet - all with potentially different effects on a child's brain - are available on the same device.

Parents used to worry only about TV use. Now school students' screen use may begin at home with TV in the morning, continue with interactive whiteboards, laptops and computers in class, smartphones at lunch and on the bus, and continue at home with TV, computer, phone and tablet. Wayne Warburton, a psychologist at Macquarie University, says US studies show that beyond the school gates, teenagers are using screens or listening to music for more than 7½ hours a day. In Australia it is more than five hours and rising.

Authoritative standards on appropriate levels of use are limited. The American Academy of Paediatrics recommends parents discourage TV for children under two and limit screen time for older children to less than two hours a day.

The guidelines, says Professor Rosen, are "ludicrous" but the need for them and constant communication with young people about technology and how they use it, remains. "It's no longer OK to start talking to your kids about technology when they're in their teens. You have to start talking to them about it as soon as you hand them your iPhone or let them watch television or Skype with grandma," he says.

He suggests a ratio of screen time to other activities of 1:5 for very young children, 1:1 for pre-teens and 5:1 for teenagers. Parents should have weekly talks with their children from the start, looking for signs of obsession, addiction and lack of attention.

Dr Warburton, the author of a book on media use, Growing Up Fast and Furious, says evidence is emerging to link screen use with disrupted sleep patterns and attention deficit problems.

"Parents say to me they would love to put some limits on their kids' media use but that it is so much a part of their identity - playing the same games as their friends, being involved with the same media - that they feel they would be losing friends, losing identity and having problems if they didn't have access," he says.

Dr Warburton says parents struggle to limit access and, increasingly, so do children. Research shows 8 per cent of video game players aged eight to 18 find it has a negative effect on their lives.

Gemma Ackroyd, the principal at Lane Cove Public School, is concerned about the "amount of visual stimulus" children receive and worries that they increasingly require it to engage in learning.

"I'm worried about a loss of time spent thinking creatively and thinking imaginatively because all the time there has to be visual stimulus, otherwise [they say] 'I'm bored'," she says.

Primary-school children can be "very savvy but very naive", she says. "There is a great need for parents to be very vigilant about the use of all this technology, to set very strict parameters."

-Sydney Morning Herald