Persistence of vision means an illusion or the retention that happens in brain in association with ocular vision within a fraction of seconds. It is a process of persisting vision or a scene optically for a second before the image gets merged or is changed into another. Optical illusions and delusion are different forms of visual perception. These perceptions are always associated with vision and a quick change in the vision causes the previous image to persist in the brain or gets merged to the next one. This can cause the blending of multiple images.