Abstract: A three-dimensional display is disclosed which uses a variable focal length lens through which two-dimensional images of an object are viewed. In one embodiment, a sequence of different images representative of cross sections of the object along its depth dimension are presented by a two-dimensional display apparatus such as a high resolution CRT. The viewer sees these two-dimensional images of the object through the variable focal length lens. The focal length of the lens is changed in synchronization with the two-dimensional images such that each cross section image is seen at a different focal length, thus resulting in a three-dimensional image of the object. The rate of change of the two-dimensional images and the focal length of the lens is higher than the retention rate of the eye of the viewer, thus the images presented appear to fuse into a coherent three-dimensional image.