Rarely do you see a celebrity wear a dress on the red carpet if another celebrity has already been photographed in it. But this season stars can’t get enough of the optical illusion dresses in Stella McCartney’s Fall 2011 collection. We think we know why. The sexy, figure-flattering sheaths manage to do two things at the same time: enhance curves and take off inches. McCartney uses artful “color blocking” to trick the eye much like a artist does. The lightest color on a canvas draws attention to an area while a darker color makes a section recede into the background. McCartney took the concept a step further and used black side panels to literally “draw” in an exaggerated waistline. See which of the following 8 stars wore their McCartney dress the best.