In addition to impacting our circadian system, light reveals the many intersecting spatial planes that make up the environment.38 Architectural features can be used to provide information about the environment and therefore improve navigation in the space.39 Light reveals visual information by providing a spatial reference for self-position and location of obstacles within a person’s surroundings. For example, removal of visual cues by closing the eyes has been shown to result in increased body sway.38, 40 Therefore, lighting schemes that reveal or enhance architectural features should be used to aid navigation and orientation in the built environment.
Nightlights that both reduce the risk of falls and help to maintain sleep should be used.36 The nightlights should provide dim illumination to the local environment (1 to 3 lux at the cornea), but also provide enhanced spatial perceptual information about the surroundings. Nightlights accent the rectilinear architectural features in the room, highlighting essential vertical and horizontal information people need to promote postural stability while navigating in an otherwise dim environment. Since the nightlights are only on when motion is detected, they do not require the occupant to search blindly for a light switch that, when found, would then activate a bright, ambient lighting system. They are on only when a person needs to move through the space at night.