Teenagers more sensitive to light - study

It is normally believed that teenagers are programmed to wake up late, but new research has suggested that simply turning down the lights at night could help them get to sleep - and make it easier to get up in the morning.

The study suggests that delaying school start times, which has been suggested as a way to fit in with young people's sleep patterns, will not help youngsters get enough rest.

The research, by academics at Surrey University and Harvard Medical School, took into account factors such as whether someone is naturally a morning or evening person, the effects of natural and artificial light on body clocks and the typical time of an alarm clock.

the study noted that it is accepted that teenagers like to sleep late and struggle to get up for school, and a common explanation for this is that their biological clocks are delayed.

There have been suggestions that delaying lessons would allow youngsters to stay in tune with their sleep needs, it says.

But mathematical modelling found changing school start time in the UK would not help reduce sleep deprivation.

Most teenagers' internal clocks would just drift later, and in a matter of weeks they would find it just as hard to get out of bed. Instead, the research suggests the problem is teenagers' exposure to light.

Getting up late in the morning leads to them leaving the lights on later at night, which delays their biological clock, in turn making it harder to get up.

The study says the biological clocks of young people are particularly sensitive to light.

Instead of moving school times, the modelling, suggests that young people should be exposed to bright light during the day, with the lights turned down in the evening and off at night.

Lead author Dr Anne Skeldon said modern lifestyles made it harder for people to get up.

"If you were to look at teens who were hunter gatherers, they wouldn't have had a problem getting up in the morning," Dr Skeldon said.

Turning off the lights includes switching off devices such as tablets and smartphones.
The modelling is published in Scientific Reports.

Associated Press