This article, which states, “sleeping with any lights on is considered detrimental to getting a good night’s rest,” tells us sleeping in a not-dark room is connected to depression, obesity, high blood pressure (hypertension), heart disease, and type 2 diabetes.
This website states “research suggests that women who live in areas with high levels of external light at night (street lights, for example) have a higher risk of breast cancer.”
This study concluded “artificial light at night is significantly correlated for all forms of cancer as well as lung, breast, colorectal, and prostate cancers individually. Immediate measures should be taken to limit artificial light at night in the main cities around the world and also inside houses.”
This study states “epidemiological studies [suggest] a general link between artificial light exposures and the risk of obesity and diabetes.”
This medical websitediscusses a study concluding that “sleeping with a light on can play havoc with insulin levels and consequently impair the response to glucose.”
This Washington Post article states “[a] 2022 study involving over 550 adults 63 and older [found]] any light exposure during sleep was associated with higher prevalence of obesity, diabetes and hypertension.”
This study concluded “increasing outdoor nighttime light intensity surrounding residences was associated with shorter sleep duration in older residents in China.”