We measure and visualize the ability-to-see, from the human eye, as that ability-to-see propagates through space. "Biological veillance flux" is a metric of sensory precision emitted from the eyes and falling on objects, with much greater detail than merely tracking the center of the eye's field of view. This work makes it possible to "see sight" and "measure sight" as the "sight" travels through three-dimensional space. In earlier work we measured veillance flux from electronic sensors and cameras. Now, we examine biological veillance flux. The result is a method to detect radiation of information-bearing optical sensitivity, as opposed to radiation of ordinary light energy in the opposite direction. These measurements can be used as an augmented-reality visualization of human sight. They can serve as an interactive score tracking how much a target is seen. Additionally, they could serve as a data-rich metric of visual precision directed by human eyes toward control panels in industrial applications, or as a metric of visual precision directed by human eyes towards printed material or digital media, for advertising, arts or entertainment applications. Extramissive optics, as a new field of research, is thus expanded into the biological realm.