I bought this book after hearing a lecture by Russell Foster. He is one of the most engaging, eloquent speakers in person, and this is reflected by his precise, understandable prose in this book.
Occasionally, the book strays into more technical areas, but the authors anchor these passages to questions more pertinent to everyday life. The authors guide the reader through passages unveiling their work on the visual pathways in the brain, and studies related to the circadian rhythms on which we all subconsciously rely.