Sometimes, in the name of security, bright floodlights are installed in outdoor urban settings — often in low-income communities. Underlying this approach is the common assumption that the illumination of dark city spaces on its own acts as a crime deterrent. However, a quick review of research on the subject presents a more complicated perspective.
Multiple studies conclude that an abundance of security lighting, in addition to being unpleasant to the eyes, is a poor strategy for increasing visibility and lowering crime rates. A 2009 report by The Royal Commission of Environmental Pollution in the UK recommends public investment in lighting infrastructure as one component of crime reduction campaigns, but additionally describes how overly bright outdoor security lights can “actually aid criminals by creating glare, which encourages passersby to look away, and deep shadows in which to hide.”
In its 2015 report Cities Alive: Rethinking the Shades of Night, the multinational professional services firm ARUP also states that overly lit nightscapes can both reduce vision and, in certain cases, signal that one has entered an unsafe place. Crucially, the ARUP report then references Jane Jacobs and her concept of “eyes on the street,” which describes how the presence of watchful community members (or even strangers) can deter crime and make a place safer. Without this kind of informal community control, the addition of lighting may not actually improve safety.
Indeed, lighting can facilitate a greater sense of community when done right. A 2002 UK government report that summarizes the relationship between lighting and crime in 13 US and UK studies attributed the average 20% reduction in recorded crime less to “increased surveillance and deterrent effects,” and more to how “lighting increases community pride and confidence and strengthens informal social control.”
Making sure that all people feel safe to navigate public space in their own communities is a goal worth striving for. The addition of artificial lighting can help this process, especially when co-designed with community members. But the locations where lighting is added, as well as what or whom it is meant to make visible, can be complicated political questions.  Lighting works best when it is dignified, sensitive to local dynamics, and makes people feel welcome to spend time in public. Conversely, oppressive lighting stifles public life, leading to greater degrees of alienation and higher perceptions of unsafety.
 There is a disturbing history of racist laws requiring certain populations to remain visible at night: for example, the 18th century Lantern Laws in New York State that targeted Black, mixed-race, and indigenous enslaved people. For more on this subject, see Dark Matters by Simone Browne.