A marker device for producing paint marks on an eye is disclosed. The marker device comprises: a handling unit and a marker unit coupled to the handling unit for rotation with respect to the handling unit about a rotational axis the marker unit including a plurality of at least two spaced apart marking surfaces and having a rotationally symmetric distribution of weight with respect to the rotational axis wherein the coupling between the handling unit and the marker unit permits the marker unit to rotate due to gravity relative to the handling unit into an equilibrium position.
