For the tech-obsessed who use their smartphones, laptops and tablets right before bedtime, a small Columbia University study suggests that inexpensive amber-tinted glasses might help ensure better sleep.
According to a Chicago Tribune report, the glasses block the blue-wavelength light emitted from many hi-tech devices. That light suppresses the brain's production of melatonin, a hormone that regulates sleep and wake cycles.
But in the study, researchers found that adults diagnosed with insomnia got about 30 minutes more sleep when wearing wrap-around amber lenses for two hours before bedtime.
"We expect that blue-light exposure before bedtime might contribute to sleep difficulties or exacerbate sleep problems in individuals who already experience difficulties, so we were not surprised there was an improvement in sleep quality," said study author Ari Shechter, an assistant professor of medical sciences at Columbia University Medical Centre in New York City.
"These kinds of glasses are very widely available, probably for $5 to $10, although more expensive options might be available for different styles," added Shechter, who doesn't have a financial stake in the findings.
Insomnia symptoms such as difficulty falling or staying asleep, frequent awakening or disturbed sleep occur in as many as one-third to one-half of adults, according to background information in the study. In addition, an estimated 90% of Americans use light-emitting electronic devices – such as tablets, smartphones and computers in the hour before bedtime, despite the sleep-inhibiting effects of this blue-light exposure.
The report says in the new study, 14 adults with chronic insomnia wore wrap-around, amber-tinted glasses or clear placebo glasses for two hours before bedtime for seven consecutive nights. Four weeks later, participants repeated the process with the other set of glasses. In addition to getting about a half-hour more sleep on nights after wearing the amber lenses, participants also reported better-quality sleep and an overall reduction in their insomnia symptoms.
A slight reduction in the time it took amber lenses-wearing participants to fall asleep was noted, though it wasn't statistically significant. "It is possible the intervention would be more effective in speeding up time to fall asleep in individuals who have difficulty falling asleep as their chief sleep complaint," Shechter said.
Many smartphone screens can be adjusted to emit amber instead of blue light, which would be another step toward reducing insomnia symptoms in those affected. Blue-wavelength light is also emitted from many light bulbs and LED light sources increasingly being used in homes because of their energy efficiency and cost-effectiveness, he noted. "Now more than ever, we are exposing ourselves to high amounts of blue-wavelength light before bedtime, which may contribute to or exacerbate sleep problems," Shechter said.
"We believe this to be an important and timely study, as it describes a safe, affordable and easily implemented intervention for insomnia," he added.
"Avoiding exposure to light from light-emitting devices before sleep would be the best approach, but using other techniques to block the blue light can help if the devices will continue to be used," Shechter suggested.
The report quotes Dr Raman Malhotra, a spokesperson for the American Academy of Sleep Medicine and wasn't involved in the research as agreeing with Shechter that the research should be replicated in larger numbers of patients with insomnia, possibly over longer periods of time. But Malhotra said some doctors are already recommending patients with insomnia wear amber-tinted glasses before bedtime, reasoning there's little to lose.
"I look at cost or risk compared to possible benefit, and in this case I feel cost and harm are minimal compared to benefits in patients' sleep," said Malhotra, an associate professor of neurology at the Washington University Sleep Medicine Centre in St Louis.
"Very large portions of the population have trouble sleeping because of the light coming from their devices, and this is a very reasonable thing to use," he added.
The use of light-emitting electronic devices before bedtime may contribute to or exacerbate sleep problems. Exposure to blue-wavelength light in particular from these devices may affect sleep by suppressing melatonin and causing neurophysiologic arousal. We aimed to determine if wearing amber-tinted blue light-blocking lenses before bedtime improves sleep in individuals with insomnia. Fourteen individuals (n = 8 females; age ± SD 46.6 ± 11.5 y) with insomnia symptoms wore blue light-blocking amber lenses or clear placebo lenses in lightweight wraparound frames for 2 h immediately preceding bedtime for 7 consecutive nights in a randomized crossover trial (4-wk washout). Ambulatory sleep measures included the Pittsburgh Insomnia Rating Scale (PIRS) completed at the end of each intervention period, and daily post-sleep questionnaire and wrist-actigraphy. PIRS total scores, and Quality of Life, Distress, and Sleep Parameter subscales, were improved in amber vs. clear lenses condition (p-values <0.05). Reported wake-time was significantly delayed, and mean subjective total sleep time (TST), overall quality, and soundness of sleep were significantly higher (p-values <0.05) in amber vs. clear lenses condition over the 7-d intervention period. Actigraphic measures of TST only were significantly higher in amber vs. clear lenses condition (p = 0.035). Wearing amber vs. clear lenses for 2-h preceding bedtime for 1 week improved sleep in individuals with insomnia symptoms. These findings have health relevance given the broad use of light-emitting devices before bedtime and prevalence of insomnia. Amber lenses represent a safe, affordable, and easily implemented therapeutic intervention for insomnia symptoms.
Ari Shechter, Elijah Wookhyun Kim, Marie-Pierre St-Onge, Andrew J Westwood
[link url="http://www.chicagotribune.com/lifestyles/health/sc-hlth-amber-tinted-glasses-better-sleep-0103-story.html"]Chicago Tribune report[/link]
[link url="http://www.journalofpsychiatricresearch.com/article/S0022-3956(17)30859-2/fulltext"]Journal of Psychiatric Research abstract[/link]