DB RCT for Specialized Phototherapy in Parkinson's Disease.

This is a pivotal study to determine whether light therapy can improve non-motor and motor function in Parkinson's disease, on top of current best medical treatment.

Inclusion Criteria: Diagnosis of Parkinson's disease as determined by the study PI, in keeping with the UK PD Society Brain Bank Criteria for the Diagnosis of PD Responsiveness to dopaminergic medication, as judged by the rater, and have been using treatment for at least the past 1 year Relatively good eyesight as attested to by participants (Corrective lenses of at least 20/60) Stable levodopa and other anti-PD medications for at least 28 days prior to screening - Exclusion Criteria: Diagnosis of an atypical Parkinsonian syndrome Significant OFF state or bothersome dyskinesias that in the judgment of the rater, would interfere with participation in the study. An anticipated need for a change in dopamine replacement therapy, concomitant medications, OTC/supplements, or other alternative therapies during the participant's involvement in the investigation History of previous light therapy use for PD \-