As our visual perception is increasingly flooded with stimuli, potential ways of perceiving space have also been affected to a greater degree. The viewer is deprived of the right to form an independent opinion, and there is a concomitant need for new spaces of freedom. There is a need for a subjectivity capable of constantly renewing and expanding the borders of perception. Viewers must be given free play to arrive at their own individual interpretation in order to make autonomous perception possible. This monograph describes the construction of reality through the cognitive subject, and, associated with this, potential ways for producing space. The book studies methods for exposing, through indeterminacy, the definition of space to a larger field of possibility within personal interpretation, and thus virtually debordering space. Against a historical background of past attempts to deborder space visually, new possible ways of indeterminately defining space through the modulation of light are shown. The analysis of various modulation phenomena is illustrated with references to works of art, and the phenomena are studied with a view to integrating them in the actual production of space. The modulation of light has the potential of creating diffuse and ambivalent characteristics on space-defining surfaces. This fuzziness offers an opportunity for a freer interpretation of spatial definition and thus also for debordering space due to the process of perception. New materials and technologies can be used to create spatial worlds that open up genuine, hitherto unknown realms of cognition and experience. Based on multilayered, ambiguous spatial situations, according to the author, new open spaces of perception are possible and thus an expansion of human consciousness as well with respect to the world around us.