The amber lenses used in the insomnia study block out a substantial portion of blue light but do not result in an overall dimming of the light levels reaching the eye. Orange lenses (not tested) may be more effective for improving sleep because they block out blue light almost completely and reduce the intensity, or brightness, of light. Credit Ari Shechter

Those sleepless nights starring at a tablet or a smartphone may be alleviated by simply wearing an amber-tinted pair of glasses.

Researchers from the Columbia University Medical Center have learned that amber-tinted lenses could block the blue light from electronic devices that leads to worsening the symptoms of insomnia.

About 90 percent of Americans use light-emitting electronic devices in the hour before bed, including smartphones and laptops. This behavior is associated with the symptoms of insomnia.

Smartphones, tablets and other light-emitting devices are lit by LEDs, which have a peak wavelength in the blue portion of the spectrum, which suppresses melatonin and increases alertness.

The researchers examined 14 individuals with insomnia who wore wrap-around frames with amber-tinted lenses or with clear placebo lenses for two hours before bed for seven consecutive nights. They then repeated the protocol with the other set of glasses four weeks later.

The researchers found that participants got around 30 minutes extra sleep when they wore the amber lenses compared to the clear lenses and in self-reported sleep surveys, participants also reported greater duration, quality, and soundness of sleep, and an overall reduction in insomnia severity.

The findings are on par with other studies that showed the benefit of blue-light blocking lenses in improving sleep.

“Now more than ever we are exposing ourselves to high amounts of blue light before bedtime, which may contribute to or exacerbate sleep problems,” Ari Shechter, Ph.D., assistant professor of medical sciences, said in a statement. “Amber lenses are affordable and they can easily be combined with other established cognitive and behavioral techniques for insomnia management.”

Many smartphones screens can now be adjusted to emit amber instead of blue light, which could help improve sleep conditions.

“I do recommend using the amber setting on smartphones at night, in addition to manually reducing the brightness levels,” Shechter said. “But blue light does not only come from our phones.

“It is emitted from televisions, computers, and importantly, from many light bulbs and other LED light sources that are increasingly used in our homes because they are energy-efficient and cost-effective,” he added. “The glasses approach allows us to filter out blue-wavelength light from all these sources, which might be particularly useful for individuals with sleep difficulties.”

The amber lenses may have also reduced the blood pressure in the volunteers.

“Insomnia is often characterized by physiologic hyperarousal, which may account for the relationship between poor sleep and cardiovascular risk,” Shechter said. “Going forward, it will be interesting to examine whether this blue-light blocking approach can be useful for improving cardiovascular outcomes like hypertension in individuals with poor sleep.”