There is also the human eye limitations:

"The human eye and its brain interface, the human visual system, can process 10 to 12 separate images per second, perceiving them individually,[1] but the threshold of perception is more complex, with different stimuli having different thresholds: the average shortest noticeable dark period, such as the flicker of a cathode ray tube monitor or fluorescent lamp, is 16 milliseconds,[2] while single-millisecond visual stimulus may have a perceived duration between 100ms and 400ms due to persistence of vision in the visual cortex."

http://en.wikipedia.org/wiki/Frame_rate#Background