Comparing extra-retinal information about distance and direction

The idea that extra-retinal information about the orientation of the eyes c ould be used to judge an object's distance has a long history, and has been the issue of considerable debate throughout this century. We here show tha t the poor performance in comparison with judgements of direction has geome trical rather than physiological reasons, and discuss why previous studies have misled us into believing that information about distance is even poore r than the geometry predicts. (C) 2000 Elsevier Science Ltd. All rights res erved.