It is a habit that is damned but many Nairobians sleep with their phones by the bedside.

You never know, the mpango wa kando saved as ‘Kawaya the Mechanic’ might just call at some devilish hour.

That is besides being conscious of meetings, seminars and conferences to attend, not forgetting travelling within and abroad. 


The Sleep School in London

Just why we place smart phones under the pillow or beside the bed.

But is this necessary or healthy? 

 Dr Guy Meadows, an insomnia specialist at  The Sleep School in London told Mail Online that a 2011 study  found mobile phones to be detrimental to healthy sleep.

The survey, carried out at Stanford University in the US, tested the effect of a total of just 0.12 seconds of light exposure during the night. Participants were exposed to pulses of light lasting two milliseconds each for an hour.


Cognitive parts of the brain

This delayed the body clock and people became more alert.

Kenya’s medical practitioner Dr Richard Muraga agrees with his foreign counterpart Dr Meadows that mobile phone use in the bedroom damages more than it helps.

“Because of the way we sleep, having a mobile phone by the bed means we do wake up in the night. Going through the phone will be stimulating the cognitive parts of the brain, which may likely interfere with our sleep,” he explains.

Even so, the main problem with mobile phones in the bedroom, according to Dr Meadows and other researchers, is light: particularly the kind produced by the bright, high-quality screens on modern gadgets.


Cells inside our eyes

According to Dr Meadows, a professor of sleep medicine at Harvard University, light stimulates cells inside our eyes. Light-sensitive cells inform our body what time it is.

“This controls the release of the hormone melatonin, which makes you feel sleepy, and the waking hormone, cortisol,” he says.

All artificial light, whether from standard light bulbs or fluorescent strips, potentially inhibits the release of melatonin, keeping us awake for much longer.


A neuroendocrinologist

However, light from mobiles may carry greater effects.Why?

According to another specialist, Professor Debra Skene, a neuroendocrinologist at the University of Surrey, light emitted by phones and tablets contains a great deal of blue light which has a more stimulating effect.

“We know that because of a pigment called melanopsin, the cells in the retina are most sensitive to blue light,” says Professor Skene.

This is why reading something on a phone or tablet before bed could be more likely to keep you awake than reading a book with your bedside light.