Sluggish Magic Mouse

In trying a second diagnosis of the sluggish Magic Mouse. Under magification and light I found a tiny hair (grey, probably mine from frustration) or synthetic filament lodged between the optic's edge and the bottom cover. It was difficult to grasp with tweezer but eventually pulled out. Perhaps it was close enough to the aperature of the optic to distort the optic's image. The sluggish response seems to have remitted