New York, Dec 18 (PTI) Using amber-tinted glasses toselectively block blue light from smartphones and otherdevices in the hours before bedtime could lead to improvedsleep in individuals with insomnia, a study suggests.
Researchers from Columbia University Medical Center inthe US tested a method to reduce the adverse effects ofevening ambient light exposure, while still allowing use ofblue light-emitting devices.
Smartphones, tablets and other light-emitting devices arelit by LEDs, which have a peak wavelength in the blue portionof the spectrum.
Blue light at night suppresses melatonin and increasesalertness; the use of amber-tinted lenses that block bluelight mitigates these effects, researchers said.
The team, led by assistant professor Ari Shechter,reasoned that selectively blocking blue light in the hoursbefore bedtime would lead to improved sleep in individualswith insomnia.
To test their theory, the researchers recruited 14individuals with an insomnia diagnosis to take part in asmall study.
For seven consecutive nights, participants wore wrap-around frames with amber-tinted lenses that blocked bluelight or with clear placebo lenses for two hours beforebedtime. Four weeks later, participants repeated the protocolwith the other set of glasses.
The researchers found that participants got around 30minutes extra sleep when they wore the amber lenses comparedto the clear lenses.
In self-reported sleep surveys, participants alsoreported greater duration, quality, and soundness of sleep,and an overall reduction in insomnia severity.
These findings, published in the journal Sleep Medicine,are consistent with prior studies showing a benefit of blue-light-blocking lenses in improving sleep, but should bereplicated in larger controlled studies, Shechter said.
"Now more than ever we are exposing ourselves to highamounts of blue light before bedtime, which may contribute toor exacerbate sleep problems," Shechter said.
"Amber lenses are affordable and they can easily becombined with other established cognitive and behaviouraltechniques for insomnia management," he said.
Many smartphones screens can now be adjusted to emitamber instead of blue light, and Shechter said these settingsshould help to improve sleep.
"I do recommend using the amber setting on smartphones atnight, in addition to manually reducing the brightnesslevels. But blue light does not only come from our phones.
"It is emitted from televisions, computers, andimportantly, from many light bulbs and other LED lightsources that are increasingly used in our homes because theyare energy-efficient and cost-effective," he said.
"The glasses approach allows us to filter out blue-wavelength light from all these sources, which might beparticularly useful for individuals with sleep difficulties,"said Shechter.
The use of amber lenses also appeared to reduce bloodpressure in the study's participants, researchers said. PTISARSAR.
This is unedited, unformatted feed from the Press Trust of India wire.