Opacity maps are, besidesgaze plotsandheatmaps, a graphical representation ofeye trackingstudy results. They demonstrate which areas of a website are viewedmore often or for a long time by one or several participants.Thereby, the image of the website is obscured by a black shadow. Themore often or the longer an area has been looked at, the moretransparent the shadow gets. If an area was not fixated at all, itis black on the opacity map. This enables to quickly identify whichareas of the website were seen by participants of the eye trackingstudy. Opacity maps are the reverse of heatmaps.