Testing whole-body light therapy

Inclusion Criteria: * Individuals diagnosed with Parkinson's disease at Hoehn and Yahr stages 1-3 based on medical history and examination * Adults aged 40 years or older * Individuals able to walk independently Exclusion Criteria: * Individuals with severe cognitive impairment (Korean Mini-Mental State Examination \[K-MMSE\] score ≤ 9) making it difficult to understand and perform tasks * Patients with dementia other than Parkinson's disease dementia * Individuals with implanted medical or other electronic devices * Individuals with severe neuropsychiatric disorders * Individuals treated for alcohol dependence within 6 months prior to screening * Individuals with a history of suicide attempts * Individuals with a history of seizures * Individuals experiencing dyspnea while sitting at rest * Individuals with visual impairment preventing them from reading ordinary text even with corrective lenses * Individuals with hearing impairment preventing them from understanding conversation even with a hearing aid * Individuals who have participated in two or more clinical trials in the same year or in another clinical trial within the past 6 months * Women and men of childbearing potential who are planning pregnancy during the trial or who do not agree to use appropriate contraceptive methods * Pregnant or breastfeeding women * Individuals deemed medically inappropriate for participation by the principal investigator or study staff based on clinically significant findings not otherwise specified above