Insomnia affects 15 to 20% of the general French adult population and increases with age. General practitioners (GPs) are the first confronted to sleep disorders, especially insomnia.~Cognitive-behavioral therapies (CBT) have proven effective, but their implementation in everyday practice is limited, and alternative treatments are still needed.~Light not only has a great influence on the sleep-wake cycle and alertness, but also on mood and cognitive functions.~The administration time of light condition will be calculated for each individual in a modality that has no impact on the circadian phase.~Study will be conduct on an outpatient basis in general practice
Sleep disorders, especially insomnia~Attention deficits (or disorders), daytime somnolence and drug dependence~The goal is to evaluate whether light therapy could be used as an efficient alternative treatment with direct application in general practice