Control method for visibility information acquisition device and visibility information acquisition device

A control method for a visibility information acquisition device displaying a first identifier at a first position ahead of a subject and displaying a second identifier at a second position spaced in a front-back direction from the first position, the method comprising:

• a first displaying step of displaying the first identifier at the first position so as to achieve a state in which a focus of the subject is on the first position;
• a second displaying step of displaying the second identifier at the second position, and moving a viewpoint of the subject from the first position to the second position;
• a control step of controlling a display state of the second identifier according to a preset transition condition, and causing a visibility of the second identifier to transition from a reference state to an intended state different from the reference state;
• and
• an acquisition step of acquiring, from the subject, the visibility information on the second identifier during transition of the visibility of the second identifier from the reference state to the intended state,
• wherein the second displaying step issues, to the subject, a notification for prompting movement of the viewpoint.

A visibility information acquisition device comprising:

• a display unit capable of displaying a first identifier at a first position ahead of a subject, and displaying a second identifier at a second position spaced in a front-back direction from the first position;
• an information acquisition unit acquiring visibility information on the second identifier when a viewpoint of the subject is moved from the first position to the second position;
• and
• a notification unit that prompts the subject to move the viewpoint,
• wherein the information acquisition unit causes a visibility of the second identifier to transition from a reference state to an intended state different from the reference state according to a preset transition condition, and acquire, from the subject, the visibility information on the second identifier during the transition.