A work vehicle includes a work implement, a main body, a bucket position detector, a display device, and a display controller. The work implement has a bucket. To the main body, the work implement is attached, and the main body has a cab. The bucket position detector detects a position of the bucket. The display device is provided in the cab and configured to overlay and thus display work assistance information on an actual view of a work site. The display controller is configured to change displaying of the work assistance information on the display device based on a distance between the position of the bucket detected by the bucket position detector and design topography.