Artificial light at night (ALAN) is a significant environmental factor with negative effects on human health. Technological advances have significantly altered light exposure patterns, reducing access to natural light during the day and increasing exposure to artificial light during the evening and night hours. ALAN disrupts the circadian rhythm, mainly by suppressing melatonin, leading to endocrine and metabolic disorders and an increased risk of cardiovascular disease. Intrinsically photosensitive retinal ganglion cells, which modulate melatonin expression in response to light exposure, play an important role in initiating these processes. Measuring light exposure remains a challenge, despite the availability of methods such as satellite imagery and personal dosimetry. Emerging epidemiological evidence links night-time light pollution to the development of cardiovascular risk factors, including hypertension, obesity, diabetes, and atherosclerosis, as well as overt cardiovascular disease. The implications of this research suggest the implementation of measures to prevent the negative effects of ALAN by promoting exposure to bright light during the day and minimizing unnecessary lighting in the evening and at night through warm spectrum lighting, curfews, adaptive dimming systems, and dynamic smart lighting solutions. The integration of global strategies that change the urban approach to street and building lighting with individual behavior and the widespread use of smart lighting is essential to create healthier nighttime environments. Future research should further elucidate the dose-response relationships between specific lighting parameters and health outcomes, assess individual susceptibility, and evaluate the effectiveness of mitigation measures. Interdisciplinary collaboration of biologists, medical doctors, environmental scientists, and public health specialists is key to translating scientific evidence into preventive policies to reduce the health burden of nighttime light pollution.
