Healthy Happy Life Info: Is artificial light wrecking your sleep?

Smartphones, laptops and energy-saving bulbs are disrupting sleep, says an expert.

By Peter Russell
WebMD UK Health News

24th May 2013 - "The use of electricity for lighting is in no way harmful to health, nor does it affect the soundness of sleep," wrote Thomas Edison. However, one sleep expert says the father of the modern light bulb got it wrong: artificial lighting is one of the worst things for getting a good night's rest.

Professor Charles Czeisler from the Division of Sleep Medicine at Harvard Medical School in the US warns that exposure to artificial light after sunset is contributing to the growing problem of insufficient sleep in modern society. Furthermore, he says that sleeplessness in children may be mistaken for attention-deficit hyperactivity disorder ( ADHD).

Writing in the journal Nature, he argues that our problems are set to get worse because of the push towards adopting energy-saving light bulbs and the proliferation of smart phones, tablets and laptops.

However, one UK expert cautions that there is no evidence that people in the UK are more sleep deprived than 20 years ago.

Slideshow: A visual guide to sleep disorders

Circadian rhythms: Telling night from day

According to Professor Czeisler, our lack of sleep can be attributed to a number of factors, including caffeine, early starts to the school and working day and long commuting times. However, he believes we sometimes fail to appreciate how much the electric light bulb has disrupted our circadian rhythms.

"As a result, many people are still checking e-mail, doing homework or watching TV at midnight, with hardly a clue that it is the middle of the solar night," he writes. "Technology has effectively decoupled us from the natural 24-hour day to which our bodies evolved, driving us to go to bed later."

He argues that there has been a 10-fold rise in the number of working adults in the US averaging less than six hours of sleep each night over the last half-century. He says that sleep deficiency and sleep disorders increase the risk of obesity, diabetes, heart disease, depression and stroke.

Energy-saving light bulbs

According to Professor Czeisler, the situation is likely to get worse once we have abandoned the traditional incandescent light bulb and switched to energy-saving light-emitting diodes (LEDs).

LEDs are used to illuminate our laptop screens, smartphones and other electronic gadgets, and have recently become a popular choice for everyday lighting.

The problem, says Professor Czeisler, is that LED white light is typically rich in short-wavelength blue light, which is known to be more disruptive to the circadian rhythm.

Professor Jim Horne from the Sleep Research Centre at Loughborough University tells BootsWebMD there is a danger in singling out artificial light and illuminated devices as the cause of sleep problems. "I don't see any hard evidence that we adults in the UK are sleeping any shorter or worse than we did 20 or so years ago before the advent of these visual media," he says.

The only exception to this may be in children, he adds. "Also attributing obesity to inadequate sleep is exaggerated well beyond the facts."

According to Professor Horne, it is not the little glowing LEDs under the screen of our TVs, computers, smart phones and hand-held games consoles that are likely to be the problem, "but the messages and excitement conveyed by these media, which in my opinion has a much more powerful effect in keeping people awake than do these forms of light".

Tips for sleeping well

The Sleep Council has a series of tips for helping you get a good night's rest. These include:

Make sure you have a good, supportive mattress
Keep your room completely dark, using blackout curtains or an eye mask if necessary
Make sure your room isn’t too hot or too cold (16-18°C is ideal)
Keep clutter out of your room
Avoid having a television or computer in the bedroom
Turn off your mobile phone and anything with an LED display (including clocks)
Only use your bedroom for sleep and sex, not as an extension to your living room or study.