The huge increase in ownership of entertainment gadgetry is having a detrimental effect on the length and quality of teenagers' sleep, according to new research by The Sleep Council.
Almost all of the 12 to 16 year-olds surveyed have either a phone, music system or TV in their bedrooms, and two-thirds have all three.
Some 58 per cent of 12 to 14 year-old boys have a phone, music player, TV and games console in their bedroom.
This plethora of entertainment options means that many youngsters are not getting enough sleep during the nights before school days, the research claims.
Some 30 per cent say they get just four to seven hours sleep, instead of the recommended eight to nine hours for this age group.
Almost a quarter admit to falling asleep watching TV and/or listening to music or with other gadgets still running more than once a week.
"I am staggered that so few teenagers make the link between getting enough good quality sleep and how they feel during the day," said Dr Chris Idzikowski, a sleep expert at the Edinburgh Sleep Centre.
"Teenagers need to wake up to the fact that to feel well, perform well and look well, they need to do something about their sleep.
"This is an incredibly worrying trend. What we are seeing is the emergence of 'Junk Sleep' that is of neither the length nor quality that it should be in order to feed the brain with the rest it needs to perform properly at school."
While teenagers are clearly not getting enough sleep, most do not seem to care much about it. Only one in 10 respondents said that they gave it much thought at all.
When asked how they thought sleep affected them, they ranked energy levels as being the most affected followed by mood, schoolwork, hair and skin, and weight.
Four out of 10 admit to generally feeling tired, and half of the girls, especially 15 and 16 year-olds, said that they generally feel tired.
Idzikowski warned that the trend for regular sleepovers with friends is only making matters worse.
"With so many bedroom distractions, the amount of sleep achieved when sleeping with friends has to be highly questionable," he said.
"Youngsters need to be taught that a healthy lifestyle includes healthy sleep
as well as healthy food. The message is simple: switch off the gadgets and get
"A comfortable bed in a well ventilated room, free of distractions, is a good starting point in encouraging a good healthy night's sleep."
Climate change likely forced inhabitants of Indus Valley civilisation to resettle in the Himalayan foothills
Shift in weather patterns made agriculture almost impossible in the Indus Valley region
Researchers claim that the magnetic properties of a thin-film material can be controlled by applying a small voltage
Dubbed Antlia 2, the ghost galaxy sits just 130,000 light-years away from the Milky Way
Delays to the roll-out of age verification for adult websites hasn't stopped government from considering extending them to more websites