An optical device for contactless measurement of height and/or thickness. The optical device having an axial chromatic aberration in order to encode the height and/or thickness information of an object positioned in the measurement field. The optical system is anchored in a confocal architecture. A detection system decodes the information through a detection system allowing the wavelength(s) focused on the surface(s) of the object to be discriminated. A plurality of points can be measured simultaneously or successively.