Dark Mode's Shadowy Promises

Around 2016, "Night mode" or "night shift"--a screen display option that features a light-on-dark color scheme--began cropping up all over our devices. That year, Apple and Twitter released their own versions of the feature. Google and others soon followed, all of them promising to mitigate the harms of blue light exposure. They aimed to address new concerns about the impact of screens on circadian rhythms and preempt a full-blown movement against late-night screen use. Eventually, the setting promised a much vaguer set of around-the-clock benefits, including improved focus, energy savings, and reduced eye strain.