An illumination homogenizing optical element is disclosed that includes at least one optical surface having a plurality of refractive structures formed as either grooves or protrusions that, individually, are wider than the wavelength of light incident onto said illumination homogenizing optical element. At least part of the light incident onto the illumination homogenizing optical element is removed from the optical path by refraction of said light so as to provide even illumination on an illuminated surface. The illumination homogenizing optical element is advantageous over prior art illumination homogenizing optical elements in that it is easy and inexpensive to manufacture while providing sufficient optical performance.