Using laptops or iPads just before bed 'increases risk of insomnia'
Published 17/05/2010 | 11:38
Computer users should turn their laptop or Apple iPad off at least two hours before going to bed if they want a good night’s sleep, scientists say.
American researchers have discovered that human brains and sleep patterns are confused by devices that emit bright lights.
Consumer electronics, such as laptops, deceive our minds that it is still daytime, preventing sleep and increasing the risk of insomnia.
Sleep experts say the body’s natural body clock starts winding down from the day between 9 and 10pm but use of computers confuse it.
A person’s brain is biologically wired to be awake when the sun is out because bright light after dark causes the brain to stop secreting the hormone called melatonin that makes us sleepy.
Researchers say blue light from devices such as iPads, which is expected to become a popular reading tool when it is released later this month, is particularly disruptive during the night when the brain thinks it should be dark.
Human eyes are particularly sensitive to blue light, which is common during the day but not in the evening.
Experts say a good book is a far better way of resting the brain and ensuring a good night’s sleep because a bedside lamp light doesn’t affect the brain as it does not look straight into a person’s eyes.
"Potentially, yes, if you're using [the iPad or a laptop] close to bedtime ... that light can be sufficiently stimulating to the brain to make it more awake and delay your ability to sleep," Phyllis Zee, a neuroscience professor at Northwestern University and director of the school's Centre for Sleep & Circadian Biology, told CNN.
“And I think more importantly, it could also be sufficient to affect your circadian rhythm. This is the clock in your brain that determines when you sleep and when you wake up."
Alon Avidan, associate director of the Sleep Disorders Center at the University of California Los Angeles, added: “I wish people would just take a boring book – an old-fashioned book – and [read] by a lamp.
“Make sure that it's not too bright, just so you can read.
"And if they do that, I think they'll feel a lot better and they'll be able to relax."
A television sitting across the bedroom was less likely to disrupt sleep patterns because it does not beam light at us from a very close distance.