title: Stereopsis from a performance perspective.
abstract: OBJECTIVE
  A patient can demonstrate a poor stereoscopic test or task performance for reasons inherent within the test/task itself for reasons dependent on normal physiology common to all human subjects, and also for reasons that are outside of normal physiology and are unique or idiosyncratic to a particular person's visual system. This article reviews the literature for the first two reasons, but emphasizes the pathophysiology involved in the idiosyncratic and abnormal reasons.
  
  
  RESULTS
  Using control systems analysis, it is shown that deficits in stereoscopic performance can be explained by reference to the quantitative aspect of stereoscopic threshold and qualitative aspects such as speed of response, reliability-robustness, and strength of percept. The relationship between fixation disparity and stereopsis is seen to be central to this explanation.
  
  
  CONCLUSIONS
  Proceeding from diagnosis to treatment, control systems analysis offers physiologically based explanations for the corrective procedures necessary to ameliorate abnormal conditions. Several topics for applied research in stereopsis are suggested.
authors.affiliation: Michigan College of Optometry, Ferris State University, Big Rapids, Michigan, USA. J_Saladin@ferris.edu
authors.forename: J James
authors.initials: JJ
authors.lastname: Saladin
mesh_terms: D003867:Depth Perception / Q000502:physiology*; D006801:Humans; D013647:Task Performance and Analysis; D014786:Vision Disorders / Q000503:physiopathology; D015348:Vision, Binocular / Q000502:physiology