The science fiction reality
iPads can disturb your sleep
The reason for this is that self-luminous, backlit tablet computers emit a blue-toned light that tricks the brain into thinking its still daytime.
This suppresses the production of the brain chemical melatonin, which acts as a 'timing messenger' for the body and signals night-time.
See also: iPad 5 - what we know
Researchers from the Lighting Research Center (LRC) in New York tested 13 individuals who used tablets to read, play games and watch movies two hours before bedtime, at a distance of 10 inches. The results, published in the journal Applied Ergonomics, found that exposure to light from full-brightness self-luminous displays can suppress melatonin by up to 22%.
The volunteers also tested the tablets while wearing orange-tinted glasses. This colour was found to have no negative effect on melatonin production- possibly because, for us, it signals the sun setting at the end of the day.
Experts have said for years that using electronic devices and staring at screens before bed can have an adverse effect on sleep patterns, but this research has confirmed the specific impact a tablet can have, especially as they are more portable and therefore more addictive than traditional devices.
The LRC experts warn that there is more than sleep patterns at risk, advising ''Suppression of melatonin by light at night, resulting in circadian disruption*, has been implicated in increased risk for diabetes and obesity.''
They also warn that if sleep disturbances happen over a long period, as is the case with nightshift workers for example, there is an increased risk of more serious diseases, such as breast cancer.
Researchers agree that the ultimate solution would be to turn off devices at night, but ultimately this is not a viable option for most, so the recommendations are that displays are dimmed and the time spent on the device is limited before bed.
The researchers from LRC are hopeful that from their study, manufacturers will consider electronic devices that could either increase or decrease types of light depending on the time of day - reducing the blue-toned light in the evening for a better night's sleep, and increasing it in the morning to encourage alertness.
LRC are also predicting that future tablets could tailor light exposures to the user, minimizing symptoms of seasonal affective disorder, and sleep disorders in the elderly. Individuals would be able to receive light treatments while playing games or watching movies.
What a turnaround that would be.
*(a lack of synchrony between the external environment and the body's internal biological clocks)