Reading may be harmful

Do you get enough sleep at night? Honestly, I don’t and neither do a lot of my friends.  Whether it’s down to today’s hectic lifestyle or something more serious such

Do you get enough sleep at night? Honestly, I don’t and neither do a lot of my friends.  Whether it’s down to today’s hectic lifestyle or something more serious such as anxiety and insomnia, the problem is only set to grow.  But what’s to blame and is there anything that can be done about it?

New research from Germany and American suggests that you limit the use of electronic devices before going to bed. The research was based on a simple experiment: a dozen healthy volunteers spent a couple of weeks in a medical facility. They all had the same routine except for when they were told to go to bed. In dimly lit rooms, half were given iPads to read from whilst the other half were given ordinary paperback books.  They were told to read for four hours prior to bed and at 10:00pm sharp, the lights went out.  They then swapped for the following week and repeated the tests.

The results highlighted quite an obvious trend. Tablet users fell asleep, on average, 10 minutes later than book readers did and spent 10% less time in desynchronized sleep phase (this is the sleep phase when we see dreams). Blood melatonin levels of tablet users were 55% lower than those of paper book readers — and melatonin is considered ‘the hormone of sleep’ and used in insomnia treatment.

During the tests iPad readers felt a bit less sleepy in the evening and reported they hadn’t had enough sleep overnight. They generally needed a couple of more hours to fully wake up.

These figures are secondary, though. The main thing is that the respondents reported subjective differences in how they felt: iPad readers felt a bit less sleepy in the evening and reported they hadn’t had enough sleep overnight. They generally needed a couple more hours sleep to fully wake up.

However, the correlation between the level of luminance and the level of melatonin (and the quality of sleep) has been well publicised before, so what is all this fuss about?

Tablet displays, as researchers reckon, do not emit much light to significantly influence the results… There is another reason.

The scientists behind the report suggest it is not quantity, but quality of light that matters. iPad’s emits short wavelengths of the optical spectrum (for our readers who are not experts in optics, it is the edge between the cyan and the blue of the rainbow: 450 nm wavelength.)  This kind of light differs from the common ambient light and, for various reasons, influences the pathway of melatonin.

iphone-5-spectra

Some people may have doubts about the research. For example, most people don’t tend to read for four hours solid every night with a regimented sleeping routine: you put the e-reader down when you’re tired.

However, you should know that displays used in iPads, modern TVs, smartphones and PCs have a lot in common: the spectral wavelength is very similar with all of them. A wavelength peak at 450 nm, and this is characteristic of both LCD screens and OLED displays.

Things start to seem a little more serious when you add up all the time an average person sits in front of these types of screens.

No one died of lack of sleep you’d say. That statement is debatable: in the US alone, each year, a quarter million of car accidents are caused due to drivers who fell asleep whilst driving

The counter argument to all this though is that “no one died due to lack of sleep, except lab rats.”  However, even this statement is false: In the US alone, a quarter of a million car accidents are caused due to either tired drivers or drivers falling asleep at the wheel, as reported by American Academy of Sleep Medicine. Inveterate cases of melatonin inhibition, which, for instance, apply to night shifters, may increase the risk of oncological diseases, the PNAS authors noted.

So if you’ve read this far, you’re probably interested in making changes to your reading and sleeping habit. Here’s five simple steps you can take:

  1. The most obvious one is of course, limit the time you spend watching TV, sitting at the laptop, or gaming before going to bed.  Sounds simple but you may find you’ve created habits for yourself.  So, change negative habits for positive ones. Instead of reading a tablet, pick up a paperback book.
  2. Turn down the level of back-light brightness and lower the colour temperature (i.e. make the image ‘warmer’). If these parameters are fine-tuned, you can decrease the intensity of blue luminance six fold. Just make sure you also fine-tune the contrast ratio to avoid eye fatigue.
  3. If you do insist on reading with a tablet, try an e-reader with a passive screen (e-ink).  These devices reflect light instead of emitting it.
  4. Think of the light bulbs you use at home. The ones emitting most natural and uniform spectrum of luminance are old-fashioned incandescent lamps. Energy-efficient fluorescent lamps and cold-light LED lamps may emit a different kind of light, including the light with undesirable peaks in short-wavelength part of spectrum. You might as well consider using red-lit LED backlights which does not include blue part of spectrum.
  5. The most radical measure you can take is wearing special orange-lens glasses which cut off the blue part of the spectrum. The effectiveness of this approach was clinically proven in a number of scientific researches. These glasses are recommended to those working on the computer at night.

blue-backlight

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