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Reading on a Computer Screen Before Bed Is Killing Your Productivity


Technology has changed the way we work — you already knew that. Executives and business owners used to be the only people who took work home; now lots of people either take work home or work from home exclusively. The problem is not working in the evening from the comfort of your own home; the problem is that the blue light in your computer, tablet, or e-reader screen is destroying your sleep cycle and causing the symptoms of sleep deprivation, even if you technically sleep through the night.

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A new study from Brigham and Women’s Hospital (BWH) has discovered more information about how reading on screens before bed is causing sleep and health problems.

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“We found the body’s natural circadian rhythms were interrupted by the short-wavelength enriched light, otherwise known as blue light, from these electronic devices,” said study author Anne-Marie Chang, PhD, an associate neuroscientist in BWH’s Division of Sleep and Circadian Disorders. “Participants reading [light-emitting electronic device] eBook took longer to fall asleep and had reduced evening sleepiness, reduced melatonin secretion, later timing of their circadian clock and reduced next-morning alertness than when reading a printed book.”

What You Read on Matters

Reading a book made from paper before bed does not destroy your sleep cycle and circadian rhythms. The study at BWH indicates that reading on a device that emits blue light, however, does impact your ability to sleep well.

Devices that emit blue light include computers, laptops, ipads, tablets, and e-readers and smartphones.

Blue Light

“Blue light” is just that — the wavelengths of light that appear blue to the human eye. During the day, blue light is advantageous. It boosts our mood, our attention span, and even our reaction times.

Blue light at night, however, is detrimental. The blue light emitted from our screens tells our bodies that it is the middle of the day. The body responds by not producing the melatonin we naturally generate in the evening. Melatonin is a natural hormone that causes relaxation and prepares the body and mind for sleep. Harvard Medical School is careful to point out that any type of light at night is harmful to the sleep cycle, but blue light has a stronger effect and is most detrimental to our circadian rhythms.

Sleep Deprivation

If you don’t get enough sleep, you will at best feel sluggish and grumpy. You are also more likely to have an accident, use poor judgment, or develop physical problems such as high blood pressure.

In 2007, psychologist Matthew Walker took functional magnetic resonance imaging (fMRI) pictures of brains of sleep-deprived study participants. The results were profound; sleep-deprived participants had highly charged responses to stimuli in their amygdalas. This mimics the emotional reactions of some types of mental disturbances.

What You Can Do

It’s not all bad news. Try these suggestions to help yourself get everything done during the day and get the sleep you need at night: 

  • Read a paper book instead of an e-reader; 
  • Print out documents and PDFs at work if you need to read them in the evening. This way, you can read them on paper; or
  • Purchase a blue light filter for your device.

    Sweet dreams!

Tell Us What You Think

Do you read on a device before bed? What do you think of the latest research from BWH? Leave a comment or join the discussion on Twitter.

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NareshRicardoCaitlin F Recent comment authors
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What if I change the settings of my e-reader to use Sepia (yellowish) color tones?


I completely agree with this research as far as my experience with e-reader. I have purchased ebook reader 6 months ago. However I have recognised the sleep disorder in first few weeks of my habit of e-reading, then I stopped reading at night. Even If there is a requirement to read at night I dont recommend using screen lights in e-readers.

Caitlin F
Caitlin F

Hi. I’ve read all of these articles coming out about computer screens, etc, but I want to just say that some of the new techy stuff has helped me quite a bit! I have downloaded some apps to my phone, and my daughter’s phone ( She is 13), that we use to help track our sleep cycles and see room for improvement. I think perhaps the “type” of stimuli projecting from the computer/smartphone may matter as well…something to consider in… Read more »

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