Modulating the illuminated field in gaze-dependent lighting: comparative evaluation against traditional uniform illumination

• A gaze-dependent lighting concept is developed to reduce energy consumption. • Uniform and gaze-dependent lighting with various illuminated fields are compared. • Navigation and spatial experiences are assessed using subjective questionnaires. • Gaze-dependent lighting is found to increase perceived spaciousness. Gaze-dependent lighting is a strategy that dynamically modulates illumination according to the user’s gaze direction, thereby avoiding unnecessary lighting in unobserved areas. Compared to traditional uniform lighting strategies, gaze-dependent lighting demonstrates clear potential for reducing energy consumption. A key challenge, however, lies in ensuring that this approach does not compromise occupants’ visual experience. As an initial step toward addressing this issue, the present study investigates how illuminated field influences occupants’ subjective experiences during navigation and their overall impressions of spatial perception under minimum ambient illumination for safe movement. Illuminated field is defined as the angular extent of the illuminated area around the gaze direction and is operationalised by the beam angle of a head-mounted luminaire. Five illuminated fields corresponding to beam angles between 20° and 60° were tested. Forty participants experienced one uniform reference condition and five gaze-dependent conditions. The experiment found that when the illuminated field was reduced to achieve lower energy use, the 30° beam angle condition showed no significant differences from larger beam angle conditions in any subjective evaluations but was rated lower than the reference condition on most evaluation questions. In contrast, the 60° beam angle condition showed no significant differences from the reference lighting condition in more evaluation aspects and was effectively perceived as enhancing the sense of spaciousness.