Similar structure of human eye and camera

Aperture is like the pupil of the human eye, which controls the amount of light. If the pupil is enough, the light will be reduced. If the pupil is bigger, so is the aperture of the camera. However, under the condition of the same shutter speed (controlling the light entering time), the human eye does not have the same structure as the camera shutter, and can only control the light entering amount with large and small pupils.