persistence of vision
- A characteristic of vision in which the retina briefly retains an image after it, or its source, has been removed. This interval is usually approximately 0.05 second. Thus, a light that switches on and off at a frequency of greater than 20 cycles per second generally appears as non-flickering. persistence of vision and the Phi phenomenon are exploited to enable a movie or TV presentation to be perceived as consisting of continuous motion, even though they are comprised of frames.