In information media such as TV programs, digital signage, or web pages, it is often the case that information contents providers want to guide viewers' attention to a particular location of the display. However, "active" methods, such as flashing displays, using animations, or changing colors, often interrupts viewers' concentration and makes viewers unpleasant.
This paper proposes a method for guiding viewers' attention without being noticed by viewers. By focusing on a characteristic of human visual system, we propose a dynamic blur control method. In brief, our method gradually blurs the image on the display to the threshold at which viewers are aware of the modulation of the display, while the region where viewers' attention should be guided is remained unburied. Two subjective experiments were conducted to show the effectiveness of our method. In the first experiment, it was shown that viewers' attention can be guided to the unblurred region using blur control. In the second experiment, it was shown that there is a threshold at which viewers were aware of the modulation and it is below a threshold at which viewers gaze are guided. This means that the viewers attention can be guided without being recognized by them.