Unconvinced that watching a few extra episodes of Bluey was having the devastating impact on children's health that some claimed, one researcher set out to prove screen time wasn't all bad.

Newcastle University lecturer Emma Axelsson said she became interested in the topic after reading sweeping statements about the detrimental impact of screen time on kids, such as that it "scrambled their brains".

But Dr Axelsson's own research appeared to prove her scepticism wrong.

The School of Psychology lecturer and her team delved into the connection between screen time and one of the biggest factors it can impact - sleep.

The research, published in the journal Acta Psychologica, involved the help of nearly 100 families who answered standardised questions about their children's screen habits, sleep patterns and ability to concentrate.

It found greater screen time predicted shorter sleep, regardless of the time of day of exposure.

It was also associated with poorer sleep quality, communication and problem-solving.

"Despite the fact I wanted to show that screen time isn't all bad, this data said it tended to look that way," Dr Axelsson said.

"Sleep affects cognitive and language development, and if screen time is affecting (those factors), is it screen time or sleep that is causing the issues?"

She hoped to uncover links between what were considered bad TV habits for children aged three to five - such as watching more than the recommended Australian guideline of a maximum one hour, or engaging with a screen at bedtime - and poor sleep habits.

But once again, the research didn't exactly line up with her estimation.

Unless a child of preschool age was watching a screen for a great deal more than the recommended one hour - say about three or four hours - it didn't impact the quality of their sleep.

Nor did it matter a great deal if the screen was on earlier in the day or just before bed, although she noted the worst sleep habits were among children who watched for very long periods and into the evening.

The research broadly tallies with previous studies, which have found increased screen time is linked to shorter sleep and more waking up at night in infants and toddlers.

Dr Axelsson had intended to conduct the research face-to-face with her study subjects, but the COVID-19 pandemic scuppered her plans while also, ironically, leading to more screen time for many children spending long periods at home.

As part of her next stage of research, she is looking for more parents to participate in interviews face-to-face.

Dr Axelsson said it was clear spending long periods in front of screens rather than being active was taking a toll on Australian youth.

"If they're spending most of their time or a good portion of their time on screens, then they're missing out on their more active time when they could be spending engaged with other things, communicating with other people, initiating their own activities," she said.

"And then there's the sedentary aspect - they spend a lot of time not being physically active and that can be having an effect on their sleep."

But trying to ban screen time altogether was unthinkable, she added.

"It does need to be limited, but I think it's a losing battle to completely limit it."