Bright Light Therapy for Post-COVID-19 Fatigue

Inclusion Criteria: * Age 18 or above * Capable to give informed consent * COVID-19 infection confirmed by PCR test or a Rapid Antigen Test (RAT) with onset of at least three months * Reports new onset or exacerbation of fatigue after onset of COVID-19 and lasted for over two months * Scoring 7 or above for the item "worst level of fatigue during the last 24 hours" in the Brief Fatigue Inventory Exclusion Criteria: * A current or past history of bipolar disorder, schizophrenia, neurodevelopmental disorder, organic mental disorder; intellectual disabilities or substance use disorder. * Presence of contraindications to bright light therapy: for example, history of light induced migraine/ epilepsy; current use of photosensitizing medications; presence of eye disease: e.g. retinal blindness, severe cataract, glaucoma. * Significant medical condition/ hearing impairment/ speech deficit leading to incapability of completing clinical interview. * Regular shift-workers * Trans-meridian flight in the past 3 months and during the study * Currently receiving any structured psychotherapy * Self-reported untreated sleep disorders (e.g. severe insomnia, obstructive sleep apnea, restless leg syndrome), psychiatric illness (e.g. depression), or medical conditions associated with fatigue (e.g. anemia, heart failure, autoimmune disorders) * Enrolment in another clinical trial of an investigational medicinal product or device.