This dissertation studies optical toys such as the zoetrope, stereoscope, and related visual media, as elements of late nineteenth and early twentieth century children's culture, and explores their roles in perpetuating particular modes of visual and sensory engagement. Synthesizing work in the history of science and psychology, theories of childhood, and film and media historiography, the project challenges the assumption that optical toys were merely instrumental developments culminating in the invention of cinema and instead characterizes their use as a set of distinctive media practices responsible for cultivating new forms of spectatorship and interaction. Through an examination of the media artifacts and discourses in which they took part, the dissertation traces how optical entertainments transformed the demonstration of visual illusions from an amusing novelty to a basic perceptual competency by the end of the nineteenth century. Each of the four body chapters concentrates on the use of optical toys and related media within a particular context, including: optical devices in the early psychology laboratory, the stereoscope in American schools, persistence of vision toys in the home, and movable toy books as an extension of this new media culture. I argue that these optical devices are associated with specific sensory paradigms that characterize visual perception as deceptive and the eye as an organ that must be trained and brought into the realm of reason and efficiency. Optical toys thus trained children's patterns of perception and shaped their visual habits in ways that positioned the experience of visual entertainment as a form of consumption. Such an in-depth treatment of optical toys revises much existing film and media scholarship by foregrounding their role in reorganizing visual perception in developmental terms.