This thesis gives an account of the material history of the electronic screen, with a view to explicating its impact on visual culture and visuality from the nineteenth century to the present. The work argues that in its electrification, the screen has engendered its own distinctive forms of seeing and imagery. The emissive nature of this medium first emerged as instrumentation for investigating electromagnetic spectra in European physics laboratories, knowledge which made possible for the first time perception beyond the limits of visible light. Subsequently, the screen underwrote a penetrative, scopic regime of vision in the guises of wartime radar and peacetime televisual surveillance for much of the twentieth century, and upon its coupling with computing, transformed the image into a controllable and dynamic procedure. As it changed shape from a bulky cathode ray tube into a flat panel display, the screen increasingly elaborated the image out of and into informatic (over)flows across small and portable or large and architectural forms, distributing a twenty-first century visual modality of surfacing, where the networked, sensitised screen continuously exhibited transactional and phenomenological experience in graphical terms. Such contemporary techno-visual saturation now foreshadows the prospect of artificial and holographic realities, and the coming arrival of a potentially post-screen, optoelectronic enclosure of the human sensorium.