Is my iPad disrupting my sleep?

This article explains how an iPad can disrupt a person's sleep.

Using an iPad or other backlit electronic tablet in the hours before bedtime not only prevents you from falling asleep, it may also affect your alertness the next day, according to a report published in the Proceedings of the National Academy of Sciences, Dec. 22, 2014. Researchers at Harvard-affiliated Brigham and Women’s Hospital found that the light emitted by the devices reset the body’s circadian clock, which synchronizes the daily rhythm of sleep to daylight. As a result, people reading e-books took longer to fall asleep and were less alert the next morning than when they read print books instead.

During the two-week study, 12 men and women read digital books on an iPad for four hours before bedtime each night for five consecutive nights. They also followed the same routine using printed books. When they read the iPad, participants were less sleepy before bedtime but were less alert the following morning, even after eight hours of sleep.

If you’re a bedtime reader who’s addicted to her iPad, don’t despair. The researchers used a 2010
iPad set at maximum brightness. Newer iPads and other e-readers have night-reading modes.

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Study: E-readers can hurt your sleep at night

A study shows that using an e-reader at night can interfere with your sleep. Instead, read from a printed book before bed.

If you're looking forward to catching up on some sleep over the holidays, you might want to put down your e-reader and pick up an actual printed book.

A small study conducted by sleep medicine researchers at Harvard Medical School indicates that e-books can interfere with readers' sleep cycles. According to the Guardian, "Study participants reading a light-emitting ebook took on average almost 10 minutes longer to fall asleep and said they were less sleepy an hour before bedtime than they were reading a paper book."

The study involved "12 healthy young adults" who were asked to read either a printed book or an e-book before going to sleep. The e-book readers experienced less rapid eye movement sleep than their printed-book-reading counterparts, and were less alert the mornings after.

The findings don't apply to the original Amazon Kindle, according to physician and professor Charles Czeisler, one of the researchers, because that e-reader doesn't emit light. The same goes for other e-ink readers such as Barnes & Noble's Nook, the Kobo and the original Sony Reader.

But users of newer e-readers and tablet computers, including the Kindle Fire and iPad, are at risk for less restful sleep, according to the study.

It's not just healthy sleep cycles that are at risk, say the researchers, noting "recent evidence linking chronic suppression of melatonin secretion by nocturnal light exposure with the increased risk of breast, colorectal and advanced prostate cancer associated with night-shift work."

The study might prove more relevant to older readers than younger ones, however. According to recent studies by Nielsen Book, teenagers much prefer printed books over e-books.

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