Urban Eye-Level Landscapes and Sleep Health: Cross-Sectional Evidence from a Megacity Using Machine Learning for Objective and Perceptual Assessment

• Perceived safety positively linked to longer sleep duration • Neighborhood enclosure positively linked to longer sleep duration and less insomnia • Potential mediation: greenness → higher perceived safety → longer sleep duration • Potential mediation: walkability → lower perceived safety → shorter sleep duration Sleep problems are a global public health concern shaped in part by the built environment, and urbanization has heightened interest in how urban settings affect sleep. Studies on sleep and eye-level landscapes often examine single elements or a limited set of audit indicators, while comprehensive street audits are labor-intensive, limiting scalable, multi-element assessment across large areas. Moreover, perceptions may mediate the relationship between the built environment and sleep, yet current evidence is largely safety-focused and relies on self-reports or expert ratings that are vulnerable to individual bias, reducing reproducibility and generalizability and underscoring the need for more objective, population-representative measures of perceptual quality. Using computer vision and crowdsourced evaluations, this study systematically assessed diverse objective (enclosure, greenness, and walkability) and perceptual (safety, liveliness, and beauty) qualities of neighborhood eye-level landscapes in a megacity. We then investigated the relationship between these qualities and sleep outcomes among 1,089 employed adults aged 40–59 years residing on the third floor or below, and further tested the statistical mediation of perceptual qualities in the relationship between objective qualities and sleep. Results indicated that greater enclosure in neighborhood landscapes was associated with less insomnia and longer sleep, and this relationship may operate through higher perceived safety/liveliness. Greenness was associated with higher perceived safety and, in turn, longer sleep, whereas walkability was associated with lower perceived safety and, in turn, shorter sleep. By integrating urban design, environmental psychology, and public health, this study provides a broader framework for understanding how built environments relate to sleep health.