Media prophylaxis: night modes and the politics of preventing harm

This article develops the term "media prophylaxis" to analyze the ways technologies are applied to challenges of calibrating one's body with its environment and as defenses against endemic, human-made harms. In recent years, self-illuminated screens (like those of computers, phones, and tablets) have been identified by scientists, journalists, and concerned individuals as particularly pernicious sources of sleep-disrupting light. By tracing the history of circadian research, the effects of light on sleep patterns, and the recent appearance of software like "f.lux," Apple's "Night Shift," and "Twilight," this article shows how media-prophylactic technologies can individualize responsibility for preventing harm while simultaneously surfacing otherwise ignored forms of chronic suffering.