Keywords: Optical-illusion-checkerboard.svg Optical illusion -- all lines and edges are strictly horizontal/vertical and fully parallel/perpendicular to each other but may appear otherwise You might need to move back a little from your monitor to see the illusion depending on file display size and/or monitor resolution Self-made SVG created from scratch in text editor declared to be in public domain HandSVG 2012 AnonMoos frame center Alternate version using black and white only For another illusion which affects the perception of a grid of lines see File Optical-illusion-grid-lines svg Distorting illusions |