Reading Before Bed: Paper or E-Reader? What One Lab Study Found
In one small lab study, reading on a light-emitting e-reader before bed delayed the body’s sleep signal more than a paper book did. This guide explains what that PNAS study tested, what it cannot tell you about your own bedroom, and a paper-first reading habit you can start tonight.
At a glance
- What the study found: after about four hours of e-reading, people took longer to fall asleep, felt less sleepy in the evening, had evening melatonin suppressed and were less alert the next morning than after paper reading.
- How big the test was: 12 healthy young adults, in a lab, in very dim room light. It is a small test, not a verdict on your bedroom.
- Your simple rule: a paper book for the last part of the evening, with the phone charging across the room.
- Quotable line: In the lab, the paper book won, so the simplest bedtime read is still the printed one.
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Does reading on a screen really change sleep?
In the PNAS study, 12 healthy young adults read for about four hours before bed on five nights with a light-emitting e-reader, and on five nights with a printed book. Average time to fall asleep was about 26 minutes after the e-reader and about 16 minutes after the book. Evening melatonin, the hormone that signals night, was suppressed by about 55 percent on average after the e-reader, with a wide spread between people. The body clock ran later too: the melatonin rise came more than 1.5 hours later the next day. The authors also reported reduced next-morning alertness.
Why would a screen change the body clock?
Light is one of the main signals that sets the body’s clock, so the timing of bright light matters as much as its strength. The e-reader in the study was set to maximum brightness, which is one reason its result may not match your own habit. The study also tested an e-reader, not a phone. A phone gives off light too, so the same logic may apply, but the study does not prove it for your phone.
What does a paper-first reading habit look like?
The NHS suggests relaxing for at least an hour before bed, and reading a book is one of its examples. It also advises not using devices like smartphones right before going to bed. Put those two ideas together and the habit is simple.
- Switch the room to a warm, dim lamp rather than the ceiling light. Pick a level where you can read without squinting.
- Choose a short book you can finish in a few evenings, so the habit has an end point and does not turn into a late-night binge.
- Read for a fixed session of about 15 to 20 minutes after you start winding down, not as a replacement for sleep.
- Charge the phone across the room, so checking it means getting up.
- Stop when your eyes feel heavy and switch the lamp off. Skipping a night is fine; the next evening’s session is the fix.
Insider tip: put the phone in the kitchen
Plug the phone in on the kitchen counter before you sit down with the book. Reaching for it then means a walk, and that small pause is often enough to stop the scroll before it starts. Keep the book on the bedside table where you can see it.
Does reading fix poor sleep or insomnia?
No. A reading habit can be part of winding down, but it does not treat insomnia on its own. The NHS says that if changing your sleeping habits has not helped, or trouble sleeping has lasted for months, or it is affecting daily life, you should see a GP. The NHS calls insomnia short-term when it lasts under three months, and long-term when it lasts three months or longer.
If your bedtime problem is more about concentration than sleep, our article on losing focus while reading covers that side. For the phone itself, the phone in bed plan is the place to start, and dimming the lights pairs well with a paper book. The wider evening sits in the adult bedtime routine.
Changing your bedtime habits has not helped, you have had trouble sleeping for three months or more, or poor sleep is affecting your work, mood or daily life. Do not start, stop or change any sleep medicine or supplement because of this article. Ask your GP or pharmacist about what suits you.
This habit sits in Tiny Habits, and the sleep side of the same topic is in Sleep & Relaxation.
Reading before bed: your questions
Is reading before bed good for sleep?
It can be, when it is a calm, paper-based wind-down kept away from bright screens. Reading does not guarantee sleep, and it is one part of winding down rather than a fix for poor sleep.
Is a paper book better than a Kindle before bed?
In the PNAS lab study, the printed book caused less delay to sleep and the body clock than the light-emitting e-reader did. That study was small and lab-based, so treat it as a clear direction rather than a rule for every reader.
Does reading on a phone affect sleep?
The study tested a light-emitting e-reader, not a phone. A phone also gives off light, so the same logic may apply, but the study does not prove the effect for your phone.
How long should I read before bed?
Use a short, fixed session of about 15 to 20 minutes that ends when your eyes feel heavy, rather than a set number of chapters.
What kind of book works best at bedtime?
A calm, short book you can put down easily works best. Choose something gripping only if it does not keep you awake thinking about the plot.
Can reading help me fall asleep faster?
It can help you wind down, but it is not a sleep treatment. If sleep stays difficult after changing your habits, the NHS advises seeing a GP.
Should I use a dim lamp for reading in bed?
Yes, a warm, dim lamp keeps the room calm and is kinder on the eyes than harsh overhead light. Pick a level where you can read without squinting.
How long until a new bedtime habit works?
There is no fixed number of days. Keep the routine steady for a few weeks and judge it by how you feel when you wake up.
When should I see a doctor about sleep problems?
See a GP if the trouble has lasted three months or more, if changing your habits has not helped, or if poor sleep is affecting your daily life.