<正>Dear Editor,A 74 years old male patient with history of Parkinson disease and vascular dementia presented to the eye clinic with his wife,who is his primary caregiver.The patient reported a multiple year history of complaining of'flies'around his head,which were a source of considerable agitation.He was so bothered by constantly seeing these flies that he carried a custom flyswatter with him(Figure 1)at all times.His