Muller-Lyer Illusion: An optical illusion where two lines with arrowheads at the ends appear to be of different lengths due to the presence of inward or outward facing arrowheads at each end.
Ponzo Illusion: An optical illusion where two identical objects placed on converging lines appear to be of different sizes due to the surrounding context.
Hering Illusion: An optical illusion where parallel lines seem curved or bent due to the presence of radial lines.