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 includes at least two spaced apart marking surfaces and has a rotationally symmetric distribution of weight with respect to the rotational axis. A 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.
