Bedtime reading: five format trade-offs

Compared with print, light-emitting e-readers can delay sleep, reduce REM sleep, and leave readers less alert the next morning.

For long or complex texts, paper often modestly improves retention of details and sequence, though results are not universal.

Backlit LCD reading causes more visual fatigue and less blinking than paper or E-ink, which can contribute to dry-eye symptoms.

E-ink readers resemble paper for visual fatigue, unlike backlit tablets, so device type matters more than digital versus paper.