 After a brain injury BI , patients complain in particular about sequel fatigue. This symptom affects about 50 of the patients; it is severe, with a repercussion on quality of life, reeducation and occupational reintegration, and persists often at a distance of the accident. The investigators hypothesis is that patients who presented a severe BI could benefit from a treatment by withe blue enriched bright light in order to improve fatigue and quality of life. 