Schools in Glasgow are running a trial of "sleep lessons" to promote a healthy sleep routine and change bad habits such as late night TV.
The lessons aim to help children learn more effectively, be calmer and enjoy better mental health.
They teach pupils about the importance of getting at least nine hours' shut-eye a night and avoiding taking cellphones, laptops and game consoles under the covers with them. Although experts say pupils should be sleeping for more than nine hours a night, some get as little as four.
The charity Sleep Scotland, which is running the lessons, says sleep deprivation makes children too tired to concentrate because their brains can't work to full capacity. "You wouldn't send somebody to school without having the right amount of food, so why would you send them without enough sleep," said director Jane Ansell.
The charity is urging Scotland to extend the trial from the current four schools. Sleep Scotland originally worked with those with special support needs but found they were being approached by more and more parents whose kids could not get into a healthy sleeping routine.
Some of the young people who went to the charity's clinics, apparently suffering from serious syndromes such as attention deficit disorder, were in fact suffering from lack of sleep.