Selectively blocking blue light in the hours before bedtime can lead to improved sleep in individuals with insomnia, according to a small study conducted by a team at Columbia University Medical Centre.
Fourteen individuals with an insomnia diagnosis took part in a small study and for seven consecutive nights, wore wraparound frames with ambertinted lenses that blocked blue light or frames with clear placebo lenses for two hours before bedtime. Four weeks later, participants repeated the protocol but switched glasses.
The amber lenses blocked out a substantial portion of blue light but did not dim light levels reaching the eye. The researchers hypothesise orange lenses (not tested) may be more effective because they block blue light almost completely and reduce light intensity.
Participants got around 30 minutes of extra sleep when they wore amber lenses compared with clear lenses. They self-reported greater duration, quality, and soundness of sleep and an overall reduction in insomnia severity.
Amber lenses are affordable and they can easily be combined with other established cognitive and behavioural techniques for insomnia management
The findings are consistent with prior studies but should be replicated in larger controlled studies, said study lead Dr. Shechter. “
Amber lenses are affordable and they can easily be combined with other established cognitive and behavioural techniques for insomnia management. I do recommend using the amber setting on smartphones at night, in addition to manually reducing the brightness levels.” Blue light is also emitted from televisions, computers, many light bulbs and other LED light sources increasingly used in homes.