Sleep is Medicine

WHY WE SLEEP: Unlocking the Power of Sleep and Dreams, by Matthew Walker. (Scribner, $27.) The director of Berkeley’s Sleep and Neuroimaging Lab makes the argument for why sleep is essential to our well-being: “to reset our brain and body health each day.” His book is dense with information, but Walker is adroit at presenting his findings and their implications in language accessible to the lay reader. And, he says, it really is true that you’ll have a harder time falling asleep if you’ve been reading a book on an LED device than you will after reading one on old-fashioned paper.
https://www.nytimes.com/2017/10/19/books/review/10-new-books-we-recommend-this-week.html