Why First-Class Cabin Lights are Dimmed for Night Landings (It’s Not for Sleep)

Flight crews dim cabin lights during night takeoffs and landings not for atmosphere or passenger rest, but for emergency ocular acclimation. If an emergency evacuation occurs, passenger and crew eyes need to already be adjusted to outdoor darkness so they can spot exits, obstacles, and terrain without losing 15–30 seconds of visual adaptation inside a smoke-filled or dark aircraft.