Aim for a "wash" of light rather than "spots" to minimize eye fatigue.

This guide explores how the physics of light interacts with human biology and psychology to shape our experience of the night. 1. The Physics of Outdoor Light

Measured in Kelvin (K). Outdoor lighting typically ranges from 2700K (warm/amber) to 4000K+ (cool/blue-white). Blue-rich light scatters more easily in the atmosphere, contributing to light pollution. 2. Human Vision and the Night

Glare occurs when a light source is significantly brighter than its background. It causes discomfort glare (annoyance) or disability glare (reduced ability to see). Shielded "full-cutoff" fixtures reduce glare and improve visibility.

3000K or lower is recommended for residential and park settings.