The present invention relates to a method and an apparatus for establishing residual stresses in objects, in particular in coated objects, and to a method and an apparatus for coating objects. The method comprises: impinging a surface (8) of the object (5) with laser light and generating a hole or a pattern of holes and/or locally heated points in the object (5); establishing the surface deformations by an optical deforming measuring method after the object (5) is impinged by laser light; establishing the residual stresses present in the object (5) from the measured surface deformations, wherein the generation of the hole pattern is carried out by an optical scanning apparatus which comprises an optical deflection and/or modulation arrangement for controllable deflection and/or modulation of the laser light, and/or a focusing arrangement for controllable focusing of the laser light.