A lens having an extended range of focus is made of a transparent material and has two optical surfaces. The lens defines an optical axis and a focal power distribution (Ftot) which, in relation to a plane perpendicular to the optical axis, changes as a function of the radial height (r) and of the azimuth angle (phi) of the aperture between a calculated basic value of the focal power (Flens) not equal to zero and a maximum value Fspiral max(r, phi).
