Using tablets and e-readers before bedtime may harm sleep quality, according to a recent study published in the Proceedings of the National Academy of Sciences. The study, performed at the Harvard School of Medicine, showed that people who used these devices within a few hours of sleeping took longer to fall asleep and had less REM sleep compared to people who read conventional books before bed. In addition, the study found that those using the tablets and e-readers before bed also reported being more tired and less alert the following day.
The researchers suggest that these electronic devices emit more blue wavelength of lights than normal light. With more exposure to blue light than normal, a person's release of the sleep-inducing hormone, called melatonin, is disrupted. When melatonin release is disrupted a person's natural circadian clock will be affected. In essence, there are real world impacts on person when exposed to devices emitting blue light prior to bedtime.
While the study was conducted with a limited number of subjects, it does suggest that people should be cautious about using devices that emit increased blue light prior to attempting to sleep. Quality sleep could be promoted by not using these devices within 4 hours of bedtime and switching to conventional reading materials instead. This may be a tough proposition, as another study indicated that as many as 9 out of 10 Americans may use an electronic device within one hour of bedtime.
Another possible solution, for those who'd rather not ditch their tablets and e-readers before bed, is blue-blocking anti-glare lenses. These new anti-glare lenses, called Crizal Provencia lenses, are currently provided at Coastal Vision. They were initially designed to filter out the blue light component of sunlight, as this wavelength of light was shown to be associated with increased damage to retinal cells and increased risk for macular degeneration. But, given the information of this recent study, these new Crizal Provencia anti-glare lenses may now also help in reducing the sleep disrupting effect of tablets and e-readers.
With such widespread using of tablets and electronic devices, this is certainly an interesting and relative study. As always, we'd love to hear from you.