Tablet computers ‘suppress melatonin’ – research

Monday 27th August 2012

Exposure to light created by tablet computers can suppress melatonin production in the body and harm sleep quality, a newly-published research paper has confirmed. The Lighting Research Center (LRC) at Rensselaer Polytechnic Institute study examined the melatonin levels of participants using ‘self-luminous’ (backlit) tablet devices under a range of conditions.

It was found that a two-hour session on the devices could lower melatonin production by around 22%, representing an impact on the body’s natural circadian rhythm that would negatively affect sleep. Notably, as well as the duration of the viewing session, it was found that the distance between the display and the viewer’s eyes was also a factor in how much the light impacted on melatonin production.

While a long-established technology in some form or another, tablet computers had limited uptake amongst consumers until an explosion in popularity in recent years following the release of Apple’s iPad. Sony, Samsung, Google, Amazon and Blackberry and others also have a range of tablets, while Microsoft is readying its own major tablet release for later this year. Apple’s own iPad is in its third iteration, with a ‘mini’ version reportedly being prepared for unveiling within weeks. With more and more options available, as well as increasingly impressive performance capabilities, the market for tablet computers is set to continue growth in the coming years and these handy devices will find their way into more of our lives.

The ease-of-use and ultra portability of the devices represents a real issue when it comes to when and where they’re used, and the resultant impact on sleep quality. The expansive screen sizes – generally between 7” and 10” – mean that they’re bigger and brighter than smartphones and lend themselves to longer-form media consumption, such as TV programmes, movies and extended internet browsing sessions. With a viewing experience more akin to using a traditional computer, but without the cumbersome size, weight and even start-up and shut-down wait-times of PCs, tablets are frequently used at times when previous technologies wouldn’t have been considered – such as in bed. Part of the Rensselaer LRC’s research focused on this point, prompting a call for manufacturers to develop more ‘circadian friendly’ displays and users to dim the brightness levels when using the devices before bed.

The results of the study were published in the journal Applied Ergonomics.

Tags: sleep melatonin light ipad apple table computers

Category: Sleep Research

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