Heine's principle in vergence stimulation

When left and right pairs of vertical parallel lines are presented stereoscopically with some disparity, they fuse so that they are perceived as a single pair of lines separated in depth. Heine showed that when such line pairs are rotated about the lines of sight in the same direction and by equal amounts from the vertical, their perceived separation in depth increases, an effect which results from the increase on horizontal disparity. This report describes how certain aspects of Heine's principle can be adapted to manipulate vergence stimulation. The technique can be implemented with very simple equipment. Possible applications of this method in binocular vision management are suggested.