Work vehicle and method for controlling work vehicle

A work vehicle includes: a work implement having a bucket; a main body to which the work implement is attached, and having a cab; a display device provided in the cab and configured to overlay and thus display work assistance information on an actual view of a work site; a bucket teeth position calculator configured to calculate a position of teeth of the bucket of the work implement in an available display area of the display device; and a following process unit configured to display the work assistance information to follow movement of the bucket of the work implement in the available display area of the display device only at a position above the position of the teeth of the bucket of the work implement as calculated by the bucket teeth position calculator.