Why quickly wink to see the wheels of rotation, you can see the moment the shape of the wheel, like a still picture?
It should be the frequency of your blink and the frequency of rotation of the wheel to form a relationship, which led you to see a series of pictures are wheels in the same position, so that your brain into a short 'static' wheel picture. There is an experiment that is the same: when the frequency of rotation of the wheel and the frequency of the human eye to receive the screen is the same, we see the wheel is likely to be still!
It is because the speed of people blink is about 0.1 seconds, the human brain can not form a dynamic effect through a single image, so you can see relatively static screen.
n the rapid movement, when the human eye to see the image disappears, the human eye can continue to retain its image, about 0.1-0.4 seconds or so, this phenomenon is called visual retention phenomenon. When the human eye looks at the object, it is imaged on the retina, and the optic nerve is input into the human brain, and the image of the object is felt. However, when the object is removed, the impression of the optic nerve on the object does not disappear immediately, and the duration of 0.1-0.4 seconds Time, the nature of the human eye is called "the eye of the visual stay".
