The decrease of sleep time and quality in recent decades has led to unhealthy lifestyle and negative impacts on health and performances. A recent survey of more than 1,500 adults in the U.S. showed that about ninety percent of them often used electronic devices within an hour before bedtime (Chang et al., 2014). With the advancement of technology, more and more people use electronic devices until late at night, which may have an adverse influence on sleep.
Such unfavorable effects on sleep may be caused by the short-wavelength-enriched light generated from the electronic devices. Experimental studies have suggested that artificial-light contact may lead to higher alerting status and the inhibition of the secretion of melatonin, which have critical impacts on sleep quality (Chang et al., 2014). Such effects may disturb the normal biological rhythms.
A recent study analyzed the different physiological results from using a light-emitting device (LE-eBook) to read and from reading a traditional paper book close to bedtime (Chang et al., 2014). The study found that compared with reading the paper books, those who used the e-Reader devices spent lengthier time to fall asleep. The e-Reader users also had lower levels of melatonin and lower levels of sleepiness at night. In addition, they had lower levels of next-morning alertness with disrupted circadian rhythms.
Such studies indicated that the use of electronic devices such as an LE-eBook may have adverse effects on melatonin levels and may cause disturbance in the circadian rhythms (Chang et al., 2014). The results may help explain the increasing problems of sleep quality and duration. They also remind us of the potential influences of such technologies on health. More studies would be necessary to elucidate the more detailed mechanisms of the effects of electronic devices on sleep and health.
Chang A, Aeschbach D, Duffy JF, Czeisler CA. Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness. Proc Natl Acad Sci U S A. 2014 Dec 22. pii: 201418490.