The Effects of Bright Light Therapy on Adolescent's Sleep Quality and Well-being

Adolescents in the BWL classrooms will be exposed to the circadian stimulating bright light (600-1000lx) to maintain alertness. The programming of the LED lighting system in the intervention group (BWL) will be tuned to provide equal stimuli to the cone and melanopsin-containing photoreceptors measured at the eye height (1.2 m above floor level for sitting position) approximately in the range 4500 -5500 K (cool white light) or between 600 and 1000 lx.

Participants in DWL classrooms will receive conventional light from the same kind of equipment as used for the intervention group, only not applying high circadian stimulation(300lx). In order to replicate conventional lighting in the classrooms, the programming of the new LED lighting system in the control group (DWL) will meet the minimum requirements according to EN12464-181, or at least 300 lx measured at table height for a light source rated at 3000 K (warm white light).