Assessment of Light Therapy in Insomnia Disorder

Inclusion Criteria: * Patient aged 30 to 60 years * Insomnia disorders (ICSD-3) with sleep latency \>30min - 3 times a week * Patient able to understand the objectives and risks associated with the research and to give informed dated and signed consent * Patient affiliated to a social health insurance scheme * For women of childbearing age, effective contraceptive measure for the duration of the research (hormonal contraception, IUD). Exclusion Criteria: * \- Shift work in the year preceding inclusion * Trans meridian travel (\> 2 time zones) in the month preceding inclusion * Patient in exclusion period determined by a previous or ongoing study * Impossibility of giving the patient informed information (emergency patient, difficulty understanding the patient) * Patient under judicial protection * Patient under guardianship or curatorship * For a woman of childbearing age: ongoing pregnancy or breastfeeding * Drug treatment which can disturb sleep or the measurement of DLMO: corticosteroids by general route, beta-blockers in the evening, exogenous melatonin. * Phase delay syndrome defined according to the criteria of the international classification of ICSD-3 * Restless legs syndrome with IRLS score\> 20 * Other psychiatric disorders or addictive disorder (screening with the MINI structured interview) * Other medical conditions not stabilized (detected by clinical interview), only the diseases appearing in the following list will constitute a criterion of non-inclusion: * Chronic allergies * Neurological disorders * cardiovascular, respiratory, gastrointestinal, hematopoietic, visual diseases * diseases of the immune system * kidney and urinary tract diseases * endocrine and metabolic diseases * infectious diseases * epilepsy