 It may be seen as a yellowish horizontal bar or bow-tie shape (with "fuzzy" ends, hence the name "brush") visible in the center of the visual field against the blue sky viewed while facing away from the sun, or on any bright background.It typically occupies roughly 3–5 degrees of vision, about twice or three times the width of one's thumb held at arm's length.The direction of light polarization is perpendicular to the yellow bar (i.e., vertical if the bar is horizontal).