1. An information presentation device, comprising: a computer which is configured to receive captured images from a camera, which is configured to capture images of a face of a user; and a memory operably connected to the computer, said memory storing instructions which, when executed by the computer, performs a process including: processing the captured images to detect visual lines of the user, and convert the detected visual lines to a corresponding presentation object which presents information to the user and is displayed on a display device proximate to the user, with different types of presentation objects for presenting different types of information to the user being respectively displayed in different areas on the display device; measuring a time span during which the user pays attention to the corresponding presentation object to determine a respective attention time; for the presentation object displayed by the display device to which the user is paying attention, specifying a recognition necessary time corresponding to the type of the presentation object to which the user is paying attention, by referring to a table in which the different types of presentation objects, including the type of the presentation object to which the user is paying attention, are shown with different corresponding recognition necessary times, each of the recognition necessary times being a minimum necessary time for recognizing a content of the corresponding type of presentation object, comparing the attention time during which the user has paid attention to the presentation object to the specified recognition necessary time, and determining from a result of the comparison a recognition degree of the user for the presentation object, wherein a higher recognition degree corresponds to a longer attention time; and redisplaying the information already presented in the presentation object in a different presentation mode corresponding to the determined recognition degree, wherein the presentation mode is designed to make the information already presented in the presentation object more noticeable to the user in case the recognition degree indicates that the corresponding attention time is too short.