Abstract: An image display apparatus enabling a wearer to observe an image free from a sense of incongruity is disclosed. This image display apparatus has an image forming unit for forming a first image and a second image mutually having a parallax, a first optical unit for guiding the first image to a first eye, a second optical unit for guiding the second image to a second eye, an interval changing portion for changing an interval between the first optical unit and the second optical unit and a signal output portion for outputting a signal corresponding to the interval to an image generating portion which generates the first and second images.