Gianni A. Sarcone designed this star illusion, using the Müller-Lyer Illusion principle. The length of a line stays the same, while its appearance can stretch or shrink because of its context, meaning the arrows attached to it. Check out this star. The blue and black radials seems to stretch and shrink, but they actually remain the same length.
Best illusion I've seen, maybe ever. The blue and black lines are NOT moving. Insanely good. pic.twitter.com/gHGx5u3vTO— Matt Lieberman (@social_brains) March 10, 2018