Fig. 4 An illustration of the appearance of Haidinger's brushes in the central visual field when a source of polarized light is viewed. The images extend from the fixation point in a pattern similar to a Maltese cross or a windmill, with the yellow brushes standing out against a blue background when white light is used. The blue arms coincide with the electric vector of the polarized light, while the yellow brushes are oriented perpendicular to the polarity of the source.