By Luke Mintz 

Sitting over 1,200 acres of Hampshire’s most beautiful countryside, Lord Wandsworth College has retained much of its Georgian character since opening as an orphanage in 1912. And this month, it is set to revert to its past in one more important way.

Across the miles of woodlands, fields, and valleys that make up the boarding school’s grounds, smartphones will now be banned during the school week as part of a tough new “invisibility” policy designed to pull teenagers away from their screens and into the real world.

Headmaster Adam Williams says impetus for the ban came from students themselves, who are worried about the seriously addictive qualities of social media. Indeed, studies show that many teenagers spend up to 10 hours each day “mindlessly swiping” on their phones, with the head of the NHS urging Facebook to release its “insidious grip” on young people.

Lord Wandsworth is one of many schools acting to limit smartphone use as the new academic year begins this week, with top public schools leading the charge.

The government has urged an outright ban on mobile phones in the classroom, and many schools are now beginning to follow this advice, says Grace Moody-Stuart, director of the Good Schools Guide, who knows a number of headteachers who have restricted smartphone use in recent months.

They say the results are extraordinary,” she told The Telegraph. “They can hear the noise of chatter, pupils are engaged and lively and talking. It just improves everything about their wellbeing.”

By now, many parents will mostly be resigned to the sight of their teenage son glued to his Fortnite match, or their teenage daughter clicking obsessively through her friend’s Snapchat story. But the implications are far more sinister than we realise, according to Jane Lunnon, headmistress of the £18,000-a-year Wimbledon High School in south London.

“We all know that our children are the victims of fundamentally commercially-driven software packages that are addictive,” she says. “The product they are selling to advertisers is our kids’ time.

“This is like a drug. Why are we letting them have this drug in school? We’re not letting them have any other drug.”

She has implemented a tough ban on phones during the school day, and warns parents in newsletters about the addictive qualities of social media at home.

She is also worried about the impact of what teenagers have dubbed Fomo – the Fear of Missing Out. By ensuring that schoolchildren are constantly aware of whatever their classmates are up to, she says, smartphones can easily make a child feel lonely.

Indeed, if all of your friends are posting Snapchat stories from a classmate’s party, your evening watching television with your parents can feel a little lame.

That’s why she has launched her ‘Jomo’ initiative – the Joy of Missing Out – where pupils are encouraged to share photos of themselves “having scrambled eggs on the sofa with your Mum”.

“Obviously it was ironic and fun,” she says, “but it really was a powerful way of making a statement, and it was incredibly popular with the girls”.

Away from the elite world of rural boarding schools, many schools in inner-city areas are enacting smartphone bans for a very different reason: to prevent their pupils from getting mugged. With muggings on the rise across the country, headteachers feel compelled to take drastic action.

But how realistic are these bans? Smartphones have, for many teenagers, become an extension of their own arm, with youngsters now seeming to live their entire social existence online. Can we really take away their gateway to a social life, even if we look down on that social life as merely a “virtual” one?

Mrs Moody-Stuart, The Good Schools director, says that after a long period of resistance she caved into demands last week to give her 11 year-old daughter a smartphone. She says the pressure on parents to provide their offspring with the latest gadgets can be immense.

And with technology finding its way into ever-more areas of our lives, is it really sensible to limit a child’s access to it? Teenagers, it is said, are part of the first ‘tech native’ generation - perhaps that should be celebrated?

Indeed, the elite Haberdashers’ Aske’s Boys’ School in Hertfordshire takes largely this view. The school admits to having a “relatively liberal” policy on smartphones, which it says are an “essential tool moving forward in an AI and digitally-dominated world”.

Whatever the obstacles, headteachers seem to agree that the tide is indeed turning against smartphones in the classroom, with teenagers themselves crying out for it: last year, a staggering two-thirds of schoolchildren surveyed said they would be happy if social media had never been invented.

“We ought to provide a Golden Oasis of time between 9am and 4pm when kids are primarily not involved in social discussion,” says Mrs Lunnon, “and are instead involved in the great adventure of learning.”