The present invention relates to a method for measuring a physiological parameter of a subject by means of an optical measurement device, said method comprising the steps of: setting into place the optical measurement device (1, 1bis) facing a skin surface (10) of the subject, so that the object focal spot of the optical objective is positioned at a predetermined skin depth, receiving by the photosensitive receiver (4) light rays from the first object focal spot, at the predetermined skin depth, analyzing the light rays received by the photosensitive receiver (4), and comparing the results of the analysis with known data, so as to determine the physiological parameter of the subject.