What is meant by ' persistence of vision'? How is this property of the eye used in movie films?
The image produced in the human eye is retained for a very short period of time after the object is removed. This phenomenon is called persistence of vision. The image formed on the retina persists for about 1/16th of a second. This means that when you are shown still pictures of a moving object at a rate faster than 16 pictures per second, the object will appear to be moving. This phenomenon is used in movies. This is because, the image of a picture stays on your retina for 1/16th of a second and you will not be able to recognize the time taken to change these pictures.