Core argument
Sleep isn't a switch you flip at midnight; it's pressure you build all day. This playbook works three levers — daytime sleep pressure, the circadian clock, and evening arousal — with concrete thresholds instead of sleep-hygiene vibes.
Counter-intuitive point
Trying harder backfires: lying awake trains your brain that bed means worry, so the correct move is to get up — the repair branch states the exact rule. Your melatonin is probably upside down too: for shifting the clock, less beats more.
What to do next
Pick the lever that matches your worst symptom, run its checklist from the outline for two weeks, and keep a one-line sleep diary. Judge the experiment by your afternoons, not by hours logged.
Connections
Companion to '光遗传学：用一束光，给大脑装上"开关"' — optogenetics gave sleep science its first causal handles on the brain's sleep–wake circuits; this guide is the practical half of that story.
Sleep Better: An Evidence-Based Playbook
Raise Daytime Sleep Pressure
Keep one fixed wake time
Weekends within 30 minutes
Bedtime may drift, wake can't
Get daylight within an hour
Overcast sky ≈ 10,000 lux
Indoor light ≈ 500 lux
Outdoor beats any window seat
Move your body daily
30 min brisk walking counts
Hard workouts end 3+ h before bed
Caffeine: half-life 5–6 h
Last dose 8–10 h before bed
Tea, cola, chocolate count too
Nap short and early
20 min max, before 3 p.m.
Set an alarm every time
Set the Body Clock
Dim lights after sunset
Overhead off, lamps on
Screens dim 1 h before bed
Know your chronotype
Night owls aren't broken — Roenneberg
Shift your schedule, don't fight it
Melatonin: timing beats dose
0.3–1 mg, 2–3 h before bed
Shifts the clock, doesn't sedate
Lower Evening Arousal
Run Ballantyne's 10-3-2-1 rule
10 h out: last caffeine
3 h out: last food and alcohol
2 h out: work ends
1 h out: screens off
Dump tomorrow onto paper
Offloads the Zeigarnik loop
5 min, notebook by the bed
Cool, dark, quiet room
18–19 °C (65–68 °F)
Blackout or a sleep mask
Earplugs or steady white noise
Same low-stakes ritual nightly
Boring book beats scrolling
No news or feeds after cutoff
When Sleep Breaks: If-Then Repairs
Awake 20+ min → leave the bed
Dim light, dull activity only
Return only when sleepy
Mind racing → don't clock-watch
Turn the clock face away
Slow exhale, no problem-solving
Snore or gasp → screen for apnea
Loud snoring + breathing pauses
Ask a doctor: Epworth scale
Test one change for two weeks
Keep a one-line sleep diary
Judge by daytime, not hours
Myths, Corrected
Alcohol: faster doze, broken night
Onset quicker, second half fragmented
REM suppressed, then rebounds
Weekend catch-up can't repay debt
Regularity beats recovery binges
One late night needs steady ones
8 hours isn't a universal law
Normal range is 7–9 h
DEC2 short sleepers are rare
It's brightness, not just blue light
Dim everything after sunset
Glasses help less than darkness