Module 2 · Attention & digital life · Moderate evidence

Technology and sleep

How phones get into your nights, and the simplest changes that help.

6 min read · Level: Beginner · Free — no account needed to read

The idea

Phones find their way into nights in three main ways. They keep you awake longer (one more video, one more message), they keep your mind switched on when it should be winding down, and their light can nudge your body clock a little later.

The light effect gets a lot of attention, but for most people it is modest. The bigger problems are usually what the screen keeps you doing — staying up later than planned, reading something stressful or exciting, replying to messages — and notifications that wake you once you are asleep.

That is why sleep specialists commonly suggest putting screens away for a while before bed and keeping the phone out of the bedroom, or at least out of reach and on silent. Using an alarm clock instead of your phone makes that much easier.

Why it works

Sleep affects mood, focus, appetite and health. Protecting the last part of the evening from screens is one of the simplest changes with a real effect on how you sleep.

A real example

The situation

Ishaan scrolls in bed until midnight most nights and wakes at 7 feeling groggy. He assumes he is just “not a morning person”.

What happened

He buys a cheap alarm clock and charges his phone in the kitchen. The first nights feel strange; by the second week he is falling asleep earlier and waking a little easier.

The takeaway

Moving the phone out of the bedroom removed the decision he kept losing at midnight.

Use this when you are…

• you scroll in bed or check your phone in the night
• you go to bed later than you intended
• you wake up tired despite enough time in bed

Common mistakes

• Relying on a blue-light filter while still scrolling until you fall asleep.
• Keeping the phone within reach “in case”, and then checking it at 3am.
• Watching stressful or exciting content right before bed.

What the evidence says

Moderate evidence: Several studies support it, but the effects are smaller, the studies are fewer or less rigorous, or results vary between groups.

Screen use in the hour before bed is consistently linked with later and shorter sleep. Laboratory studies show bright screens can slightly delay the body clock, but for most people the bigger effect comes from what screens keep them doing.

Where this comes from: Sleep and circadian research; American Academy of Sleep Medicine (AASM); US Centers for Disease Control and Prevention (CDC).

Fields that study this: Sleep science, Behavioural science.

Try it now: Plan tonight’s phone parking

1. Decide where your phone will charge tonight, outside your bed’s reach.
2. Decide what you will use as an alarm.
3. Pick a screens-away time, 30 to 60 minutes before you want to sleep.

Practise with a guided technique

• Digital sunset — (30–60 min before bed · Emerging evidence)
• Evening wind-down — (20–30 min · Moderate evidence)

Questions to think about

• What does your phone usually do for you in the last hour before sleep?
• What could replace it — reading, a stretch, talking, music?

Try this today

Tonight, charge your phone outside your bedroom or out of reach of your bed.

Afterwards, ask yourself

After a few nights with the phone parked elsewhere, what changed in your sleep?

Words in this lesson

• Circadian rhythm — Your body’s internal clock, running roughly every 24 hours, which controls sleepiness, alertness, hormones and more. Light is its main setting signal.
• Melatonin — A hormone your body releases in the evening as darkness falls, signalling that it is night-time. Bright light in the evening can delay it.