A transmission type head mounted display device includes an image display unit including an image-light generating unit configured to generate image light on the basis of image data and emit the image light, the image display unit causing a user to visually recognize the image light as a virtual image and transmitting an outside scene in a state in which the image display unit is worn on the head of the user, and a control unit configured to set, as the image light that the control unit causes the user to visually recognize using the image display unit, specific image light generated on the basis of set specific image data and changing according to elapse of time.