August M
For years, glowing screens have been blamed for restless nights. Phones, tablets and laptops were said to disrupt sleep with their blue light.
But new research suggests the problem may not be what people think.
According to the BBC, while blue light can influence the body’s internal clock, its impact from everyday devices is often overstated. Experts now say the bigger issue lies in overall light exposure and daily habits.
The blue light myth
Concerns about screens surged after early studies linked evening device use to delayed sleep and reduced melatonin.
But more recent analysis paints a more nuanced picture. One review found screen use delayed sleep by only a few minutes on average.
Professor Jamie Zeitzer of Stanford University said: “But the amount of light emitted from our screens is really inconsequential.”
He explained that many laboratory studies exaggerate the effect because participants are exposed to unusually dim conditions before bright light is introduced.
What really matters
Scientists now emphasise that total light exposure throughout the day plays a far greater role than screen use alone.
Bright light in the morning helps regulate the body clock, while lower light levels in the evening signal it is time to rest.
“The more light that you get during the daytime, the less impact the light in the evening has,” Zeitzer said.
Natural daylight is particularly important. Even a cloudy day delivers far more light than indoor environments or digital screens.
Lifestyle over screens
Experts also point to behaviour rather than brightness as a key factor. Activities on devices, such as scrolling or watching stimulating content, may keep the brain active longer.
“It is much more the content, rather than the light, that is keeping people awake from these devices,” Zeitzer said.
This shift in understanding suggests that simply enabling blue light filters may have limited effect on sleep quality.
Extreme experiment
To test the theory, one journalist adopted an intense routine, blocking out blue light with specialised glasses, blackout curtains and candlelight evenings.
While the changes did not dramatically improve sleep duration, they helped create a more consistent bedtime routine.
Researchers say such habits can act as psychological cues, signalling to the brain that it is time to wind down.
Practical advice
Rather than focusing solely on screens, experts recommend increasing daylight exposure and creating a clear contrast between day and night.
Simple steps such as going outside in the morning, brightening indoor spaces during the day and dimming lights in the evening may be more effective.
The findings suggest that while blue light is part of the picture, it is far from the main culprit behind poor sleep.
Sources: BBC
