Optics (20) for an illumination device (1), as well as an illumination device (1) comprising such optics. The optics comprise at least one lens (30) with a light entry surface (31) and a light exit surface (32). A stepped lens structure (321), such as a Fresnel structure, is formed on the light exit surface. A recurring surface structure, such as periodically arranged prominences (311) and deepenings (321), are formed on the light entry surface (31).