# Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness

Chang AM, Aeschbach D, Duffy JF, Czeisler CA · PNAS 112(4):1232–1237 · 2015



## Key finding

Reading on a light-emitting device before bed delayed melatonin, lengthened sleep onset and reduced next-morning alertness vs a printed book.



[Read the paper](https://pubmed.ncbi.nlm.nih.gov/?term=Evening+use+of+light-emitting+eReaders+negatively+affects+sleep,+circadian+timing,+and+next-morning+alertness)

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