Almost seven in 10 children have a television in their bedroom - and their parents are mostly not worried about what they are watching, a TES survey has found.
Most parents say they are not concerned that their children could be watching programmes with violent scenes, bad language or sexual content, and only a quarter use a parental control filter.
There is more concern about what children might be doing on the internet.
More than half of parents (55 per cent) use a parental control filter, the study found.
Mothers and parents of girls see the internet as a greater threat to their children than do fathers or parents of boys. They are particularly worried about adults who use chatrooms to prey on children. This could be why more parents have control filters on children's computers than on bedroom TVs.
Childnet, a charity promoting safe internet use, said it was pleased that most families use control filters. But Stephen Carrick-Davies, chief executive, said filters could lull parents into a false sense of security and that it was "not wise" to let children surf the internet in their bedrooms.
More than one in 10 children has a computer with internet access in their bedroom, and these children are more likely to come from middle-class families. Working-class children and older teenagers are the most likely to have a bedroom TV, but the TES poll reveals that 46 per cent of five to seven-year-olds also have their own set.
Four years ago, a poll for the BBC found that 63 per cent of children aged 10 to 14 had their own TV; today, 77 per cent do. DVD and internet access has doubled and ownership of games consoles has increased almost fourfold Margaret Morrissey, of the National Confederation of Parent Teacher Associations, said: ""My son, Jonathan, had a computer and TV in his room from age six, and now he works in computers and makes more money than I'll ever make. I would not get too hysterical about it but parents should be conscious of when the things are switched off. We have to accept children use their bedrooms as living spaces."
Half of all children with a bedroom TV are allowed to watch it between going to bed and going to sleep. TVs tend to be terrestrial only, although slightly more than one in five has extra cable or satellite channels. But children also have access to DVDs, video players and computer-games consoles.
The TES survey shows that one in three watched TV, one in four DVDs, one in eight used the internet and one in 10 played computer games. Six in 10 have a DVD or video player in their bedroom, and four in 10 - mainly boys - a computer games console.
The Snooks family from Little Downham, Cambridgeshire, has five TV sets - one in each bedroom, the kitchen and the living room.
Gareth, 15, said: "Pretty much all of my friends have a TV in their room. I don't normally use it to watch TV, though, but to play PlayStation games."
Bleddyn, his father, a science teacher at City of Ely college, said: "Some people don't have a TV in their own bedroom but a lot of people do. I don't think it's better or worse - it's just the way it is."
His daughter, Megan, 10, has a TV, DVD player, computer and Nintendo GameCube in her bedroom. She said: "I've fallen asleep with the TV on and woken up to find mum and dad have switched if off."
She watches TV only about once a week and finds it less alluring than roller-skating and girl guides.
The Huxley family from Bridport, Dorset, has one TV - in the living room - and argue about what to watch. Mother in the family, Ros Fry, a marketing consultant, believes TV and computers are not a good idea in bedrooms.
She said: "I don't have satellite TV because we got it once and the children just watched the music channels all the time. I think TV dulls them. It's a passive activity, whereas reading uses the brain."
Her son Max, 14, has a computer in his room, but it has only music programs on it. He describes it as a "virtual studio". "I don't crave a television,"
His younger brother, Dominic, nine, is similarly sanguine.
"I am a Lego maniac," he said. "I have a CD player, which is quite good, but my room is a bit cluttered. I wouldn't mind another TV in the house, but not in my room. It would crowd my room with all the wires. If I did have a TV in my room, I might have the urge to turn it on and stay up all night and then I'd be tired in the morning. I'll probably wait until I leave home."
PATTERNS OF SLEEP
* One in five parents says their child has lost sleep during the the past month, the most common reason being bad dreams.
* Children at key stage 4 are most likely to lose sleep because of worry over schoolwork or exams.
* One in 10 parents says their child's sleep was disturbed when they were taking Sats.
* Seven in 10 children have a television set in their bedroom. Only a quarter of parents have control filters to screen out unsuitable programmes. Half of parents whose children have access to the internet use a control filter.
* Few schools suggest times by which children should be in bed;
* 40 per cent of parents think schools should recommend bedtimes or a minimum number of hours' sleep.
During April 2006, FDS interviewed 500 parents of children attending primary and secondary, state and independent schoolsin England and Wales