Figure 1.

Diagram of light device placements. Participants were seated at a desk in a darkened room with light devices placed at a 45-degree angle to the right and left of center at a distance of approximately 80 cm. (A) During the 30-minute blue light Washout Period, 2 devices (one on the left and one on the right) fitted with amber light emitting diodes (LEDs; λ = 578 nm) were directed toward the participant, with each device centered at a 45-degree angle). (B) During the 30-minute Exposure Period, 4 devices (2 on the left and 2 on the right) were directed toward the participant, with each pair centered at a 45-degree angle. Devices were fitted with either blue (λ = 469 nm) or amber (λ = 578 nm) LEDs, according to random assignment.