To suppress, in an optical body in which a microlens array as a non-periodic structure is arranged and deployed in a wide range, occurrence of periodic optical properties in a structural unit larger than the non-periodic structure. The optical body includes a single non-periodic structure region or a collection of a plurality of non-periodic structure regions, the non-periodic structure region being composed of a single lens group including a plurality of single lenses. In the non-periodic structure region, a located state of the single lens group is non-periodic as a whole. A ratio of a size of the non-periodic structure region to an average aperture diameter of the single lenses in the non-periodic structure region is more than or equal to 25.