Environmental influences on visual hallucinations in Lewy body disease: the potential role of virtual reality

Lewy body disease (LBD), which includes Parkinson’s disease (PD) and dementia with Lewy bodies, is frequently accompanied by visual hallucinations, one of its most characteristic neuropsychiatric symptoms. These symptoms are clinically significant as they reduce quality of life, increase caregiver burden, and correlate with poorer prognosis. In clinical practice, visual hallucinations in LBD often appear under certain environmental conditions, including nighttime or low light settings, ambiguous shadows or patterns, and visual features such as furniture or decorations, suggesting environmental influence. However, this dependency has not been systematically characterized, and its mechanisms remain partially understood. Current evidence suggests that this phenomenon may arise from the interaction of reduced bottom-up visual input, excessive top-down influence, and impaired reality monitoring. Although pharmacological treatments remain crucial, adverse events and tolerability concerns often limit their use and increase discontinuation rates. Thus, investigating non-pharmacological approaches such as direct modifications to patients’ environment may provide an alternative approach to symptom management and treatment. In this Perspective article, we summarize the clinical features of visual hallucinations in LBD, review evidence regarding their environmental dependency, examine candidate pathophysiological mechanisms, and highlight virtual reality as a promising tool for mechanistic investigation and individualized environmental interventions.