The Effect of a Lighting Intervention on Sleep in Parkinson Disease

50 participants with Parkinson's disease will be recruited to complete actigraphy studies to assess sleep disturbances. For this, participants will wear an Actigraph for seven days. Thirty of these participants with sleep disturbance will go on to receive a tailored lighting intervention (TLI) to assess the effect on sleep, fatigue, and circadian entrainment via urinary melatonin levels.

Participants will undergo one week of baseline data collection using the actigraph and light meter and one night of an overnight urine collection. At the completion of the baseline week, the lighting intervention will be installed in the participants' home. Participants will be exposed to the lighting intervention for 2 hours each morning after awakening for 8 weeks. During the last week of the lighting, participants will be asked to wear the actigraph and light meter again for 7 days and collect one overnight urine sample. Participants will complete questionnaires before and after the intervention to further assess its effects.