Blue light and sleep: what the research actually says

You're tired — but wired. You're lying in bed, your mind still spinning from that last scroll session, and sleep won't come. Sound familiar? People are spending more and more evenings behind a screen, and according to research from the RIVM (Dutch National Institute for Public Health), that has a demonstrable effect on our sleep.

What blue light does to your body

Blue light — the part of the light spectrum that pours abundantly from phones, laptops and TVs — affects our biological clock. Evening exposure can lower melatonin production (the hormone that makes you sleepy) by 20 to 40%, according to RIVM research. Your body literally thinks it's still daytime.

This is one of the few claims in the blue light discussion that science firmly stands behind — unlike the often-disputed claims about eye damage during the day. Especially among teens and young adults who use a screen daily in the hour before bed, researchers see later sleep onset, shorter sleep, and more nighttime waking.

Why "just stop earlier" doesn't always work

The advice is simple: no screen for at least 30 to 60 minutes before sleep. In practice, few people manage that — one last work email, a show, scrolling in bed. Software solutions like night mode lower your screen's colour temperature, but don't change the specific wavelength range your biological clock responds to. That's a different mechanism than a lens that physically filters.

What you can do tonight

• Build in a transition ritual. Put your screen away 30 minutes before bedtime — or wear a signal that marks the end of the day.
• Dim bright ambient light in the evening, not just your screen.
• Keep it consistent. Your biological clock responds to patterns, not one-off incidents.
• Be honest with yourself about how much screen time you really have in that last hour before bed.

Where an evening pair of glasses can help

We're not claiming glasses solve your sleep problem — that's exactly the kind of promise we try to avoid in this category. What we do see: a physical habit, like putting on a light pair of glasses during your last scroll session, works for many people as a reminder to be more deliberate about those final evening hours. Our Linea weighs 18 grams — light enough to simply keep on, even on the couch, during that last episode.

Frequently asked questions

How long before bed should I stop using screens?

RIVM and Dutch sleep researchers recommend at least 30 to 60 minutes of screen-free time before bed.

Does night mode on my phone work as well as blue light glasses?

Night mode lowers your screen's colour temperature, which is a different mechanism than a lens that filters specific wavelengths. Both may play a role; neither is a guarantee.

Is blue light worse in the evening than during the day?

Yes — the effect on melatonin production is most relevant in the evening, because your body is already preparing for sleep. During the day, blue light actually plays a role in alertness.

Sources: RIVM — Screen use, blue light and sleep (2018); Hersenstichting.