Ambient vision, one of so-called two modes of vision proposed by Trevarthen and others, is important to understand the visual stability problem. Stability has many components, such as direction, position, and orientation constancies. In addition to these constancies visual fixation constancy, a tentative name, which is logically contraposition of the stabilized image phenomenon, should be considered. Author showed these constancies correspond to the types of visual field systematically. Critical value of the stability of visual space as a general measure was introduced. Minor experimental data of this value were presented.