Britons uses 4 times more artificial light today compared to the 1950s
Poor sleep associated with obesity, diabetes, heart disease and depression
Electric lights, including those which illuminate laptop computers, smartphones and tablets, often play a key role in causing people to sleep badly, a leading expert has warned.
Artificial lights disrupt the body's natural rhythm, affect chemicals in the brain and drive people to use stimulants like caffeine to stay awake longer, according to Harvard academic Professor Charles Czeisler.
Writing today in the journal Nature, the professor of sleep medicine at Harvard Medical School called for research to help develop 'behavioural and technical' ways of counteracting the ill effects of artificial light on modern sleeping patterns.

Screen breaks: Illuminated screens have been found to affect the body's circadian clock - the genetic mechanism which helps regulate sleep - 'more powerfully than any drug'
The decline in the number of hours slept per night is affecting public health, including a greater risk of obesity, diabetes, heart disease, depression and stroke in adults and concentration problems in children, he said.
While all electric light affected circadian rhythms - the natural body clock - and sleep, night-time exposure to LED lights like those in phones and computers was 'typically more disruptive' than standard electric light bulbs, he said.
'There are many reasons why people get insufficient sleep in our 24/7 society, from early starts at work or school, or long commutes, to caffeine-rich food and drink,' he wrote.


















Comment: For more information on the amazing ability of the brain to heal itself read:
Rewiring a Damaged Brain
Scots doctors to help stroke patients 'rewire' their brains by stimulating the vagus nerve
Human Brains Grow, Change and Can Heal Themselves
Reading Remediation Seems to Rewire the Brain