The ability of the human eye to continue to see the image of an object for a very short duration even after the removal of that object is called persistence of vision.
It is due to the persistence of vision that we are able to see movie pictures in a cinema hall. The pictures in the form of a long fiber are projected on the screen at a rate of about 24 pictures per second. Under these conditions, the image of one picture persists on the retina of the eye till the image of the next picture falls on the screen. and so on. Due to this, the slightly different images of the successive pictures present on the film merge smoothly with one another and give us the feeling of continuity and moving images.
