I hate goin to the movie for a couple of reasons. The really crappy 24 fps and the crappy picture quality.
The speed of one's eye might be the speed of light, but it is hard to tell. Cause remember, you aren't seeing an object, you are seeing light being reflected off of the object. taking into consideration the delay of the speed of light traveling from its source to the object and back to your eyes. And a little dely might occur again with our brain processing the image. A good way might be to find out how fast the light will get to your eyes and then finding out how fast your brain cells communicate with each other, this might give you an approximate framerate. But then again, the world doesn't work in frames, it works in movement.