Introduction rnRecurrent complex visual hallucinations are a core clinical feature of dementia with Lewy bodies (DLB) and are typically well-formed,often consisting of figures,such as people or animals [1].Despite the profound impact upon patients and caregivers in DLB,the aetiopathology of visual hallucinations remains largely unknown.In this article we discuss the anatomy of the human visual system,hypotheses of the genesis of visual hallucinations in DLB,and imaging and neuropathological studies that have attempted to understand visual hallucinations on a functional and anatomical basis.