Light therapy for circadian rhythm disorders
Light influences our body’s biological clock. When light falls on the retina, our biological clock receives a signal. This is why light therapy may be a treatment option for a sleep disorder caused by a disturbance of the circadian rhythm.
When high intensity light is offered in the morning or evening, the sleep rhythm may shift. Light in the morning causes the sleep rhythm to move backward. Light in the evening causes it to move forward.
Light therapy is usually combined with chronotherapy. Chronotherapy aims to arrive at the desired sleep rhythm by gradually moving up bedtimes. Light therapy can ease or maintain a move-up rhythm.