The image formed on the retina persists for about of a second. This means that if you are shown still pictures of a moving object at a rate faster than 16 seconds, then the object will appear to be moving. This is because, the image of a picture stays on your retina for  of a second and you will not be able to recognize the time taken to change these pictures. 

 

Hello, I have not understood this para. Please explain......

 1 image in retina remains 1/16 sec . But in movie hall image are changed at the speed of 34 images per second so it appear toi be moving

the thing is the image focused on the retina just remains for 1/16 of the second. to understand it better u can do an activity. take a small cardboard and pierce a hole on two sides(opposite sides). put a string tying both the ends. draw a cage and a bird on both the sides. as you move the string faster you can see the bird in the cage. thus we move the cardboard faster than 1/16 of a second and we see the 2 pictures in motion.

hope it helps.

See. persist means remain or continue to exist....ok..now , it is given that on the retina the image will persist only for 1/16th of a second....clear...if someone show you some images faster than 16 seconds...u will not be able to recoganise the image clearly because your retina has not sensed it yet and it is moved away from your eye...ok...

hope it hepls!!!!!!!!