This compilation of scientific abstracts and anecdotal testimonies discusses the relationship between health and light exposure.
In this second edition, Hansler compiles studies from a growing body of research related to the myriad effects of prolonged exposure to artificial light. Hansler investigates the implications of our increasing reliance on technology and how added time in artificial lighting can alter our bodies’ natural regulation systems, such as the melatonin flow that affects circadian rhythms. To encourage a more regulated sleep schedule, he posits a solution based on altering the flow of melatonin before bed by using either glasses with amber-colored lenses or minimizing blue light exposure before bed. This simple remedy vastly improves sleep quality, he says, with far-reaching effects on overall health, including cancer prevention. Hansler finds sweeping implications for this low–blue-light lifestyle: how it could regulate the sleep patterns (and therefore long-term health) of night-shift workers, boost students’ energy (and therefore academic capacities), treat seasonal affective disorder, and even moderate some kinds of mental illness. The book jumps among practical applications, such as fighting insomnia and combating jet lag, to uses that require a lengthier leap, such as mitigating bipolar episodes through darkness therapy and countering postpartum depression by regulating sleep for new mothers. Light on original research, the book frequently presents (without comment) research from disparate sources, including press releases. The result is a spectrum of conclusions ranging from generalizations to his support, which sometimes verges on product endorsement. The first half of the book, Hansler notes, remains nearly unchanged from the book’s first edition. Chapters in the second half serve as companions to those in the first, though much of the content is repeated; substantial edits would be welcome. Likewise, the book’s findings could use a more cohesive presentation.
Presents a limited number of practicable tips based on others’ research.