A changing conception of light emerged in 19^(th)-century technology and architecture. The extensive use of glass as major building material helped create a new viewing perspective and a re-assessment of light's relationship to darkness. This different visual perception found a parallel in contemporary painting, literature, and music. Viewing shadow as a metaphor for illusion, the Romantics provided an idiosyncratic definition of illusion and reconsidered its relationship to reality. Their exploration of this theme also reflects a concern with appearance relative to reality, a key issue in Romantic aesthetics. For example, H. C. Andersen presented shadow as the embodiment of one's alter ego. In music, the Romantics' concern with appearance and reality manifests in a number of uncanny scenes in the Lied and opera, in which appearance works at odds with music, thereby creating technical and aesthetic challenges for the composers. In this paper, I will show how the different viewing perspective in the Romantic era contributed to contemporary artists' changing reading of shadow. I start with a brief introduction of how 19th-century architecture initiated a changing perception of light. I continue with a discussion of how this new visual conception was translated into literature and the arts. My examples come from the artworks created toward the later part of the long 19^(th) century, including Andersen's The Shadow, a selection of French silhouette paintings, and Hofmannsthal and R. Strauss's Die Frau ohne Schatten. By re-evaluating a visual phenomenon deriving from technology and exploring its impact on contemporary literature and arts, I offer a broader understanding of Romantic aesthetics and the interconnection between major disciplines in this era.