Stabilization of Circadian Rhythms in Delirious ICU Patients Through Light Intervention

Inclusion Criteria: * Patient capable of giving consent or additionally existing legal caregiver or authorized/spouse representative in case of non-consenting patients in the intensive care unit * Male and female patients with age ≥ 18 years * Expected intensive care unit stay ≥ 2 days * Positive delirium during and up to a maximum of 30 days after study inclusion (determined by CAM-ICU, at least once per shift) Exclusion Criteria: * Participation in other clinical studies during the study period and ten days before * Previous ICU treatment during the current hospital stay * Patients with psychiatric diseases * Patients with a history of stroke and known severe residual cognitive deficits * Patients with a history of cardiopulmonary arrest or pulseless electric activity with cardiopulmonary resuscitation followed by therapeutic hypothermia during entire hospital stay * Amaurosis * History of sleep-related breathing disorders * History or suspicion of hypoxic brain damage * History or suspicion of elevated intracranial pressure in the last 7 days before study inclusion * Patient has a power of attorney or patient's provision, where he/she refuses participation in any clinical trial * The informed consent of the patient or the subject's legally acceptable representative can't be obtained in time * History of photoallergic reactions or history of visually triggered seizures * Severe eye diseases (e.g. retinopathy, glaucoma) or high sensitivity to bright light * Patients with liver cirrhosis * Patients with a probability of survival \<24h * Optic neuritis within the last 3 months * Travel across two time zones within 3 months prior to study screening * Women who are pregnant, have a positive pregnancy test, are breastfeeding or plan to become pregnant during the course of this clinical trial * Therapy-refractory blood coagulation disorder and inability to consent are exclusion criteria for a muscle biopsy