An information processing system comprises: a light emitting unit that irradiates pattern light having a specific pattern to a subject to form a texture on the subject; an imaging unit that captures the subject on which the texture is formed; a deriving unit that derives distance information to the subject based on an image captured by the imaging unit; an analyzing unit that analyzes whether or not an image abnormality is present in either one of the captured image and an image based on the distance information; and a dimming unit that performs dimming control when the analyzing unit analyzes that the image abnormality is present.