The present invention provides an optical member having a substrate and dots adjoining the surface of the substrate, the dots comprising a liquid crystal material having a cholesteric structure, the substrate including a liquid crystal layer on the face thereof adjoining the dots, and the liquid crystal layer being a layer in which the alignment of a liquid crystal compound is fixed. This optical member includes dots comprising a liquid crystal material having a cholesteric structure in which there is minimal disorder in alignment, the dots being shaped so that the maximum height thereof with respect to the diameter of the dots is large, and has a high dot pattern detection sensitivity in any direction including an inclined direction. Using this optical member, an image display device having good data input sensitivity can be provided.