Answer
The brain and human eye resemble a movie or video camera more than they do a still camera.
Work Step by Step
Imagine a light source being carried left to right across a room, taking 10 seconds for the trip.
If a camera shutter is left open for 10s, all of the light entering the lens hits the film (or sensor) and makes just one image. As the position of the light spot on the film moves, it overlaps the light from the source’s previous positions, and the final image will be a blurry streak.
In contrast, with the human eye, new images are always being formed by the retina and the brain. The light from the source’s old positions do not “accumulate” over the 10 seconds and overlap with one another to form a single image. Rather, your brain interprets the motion as a series of images. The brain and human eye resemble a movie or video camera more than they do a still camera.