title: [Shutter-glasses haploscope with eye-tracking control for fusion therapy].
abstract: BACKGROUND
  Common haploscopes require a manual input of the presented disparity and particularly prepared images; moreover, they can be used predominantly by orthoptists. We developed a device that makes possible a haploscope on the basis of a computer monitor with shutter-glasses. The presented disparity is determined with help of an eye-tracker.
  
  
  METHODS
  A patient looks at a monitor through shutter-glasses, the eyes being recorded by a camera. An eye-tracking software determines the fixation points and the angle of strabismus. Images are presented at the monitor with a disparity that is regulated according to these measurements. This is controlled by means of a software so that the disparity is gradually decreased according to the patients abilities. Diagnostic data are recorded permanently.
  
  
  RESULTS
  Any monitor contents, such as videos, TV or computer applications, can be used for fusion training or diagnostic purposes with the new apparatus. Initial investigations of patients with heterophoria or intermittent exophoria indicate a decrease of the subjective angle of strabismus by compensation and an increase of the fusional range.
  
  
  CONCLUSIONS
  The developed shutter-glass-haploscope with eye-tracking control provides several methods for diagnosis. The appliance provides automated fusion training adapted to the patient that can be done at the working place or at home.
authors.affiliation: Institut für Physik, Universität Bremen. Hans-Otto.Carmesin@t-online.de
authors.forename: Hans-Otto
authors.initials: HO
authors.lastname: Carmesin
authors.forename: Stefan
authors.initials: S
authors.lastname: Kallenberger
authors.forename: Constanze
authors.initials: C
authors.lastname: Schmidt
mesh_terms: D000293:Adolescent; D000328:Adult; D001676:Biofeedback, Psychology / Q000295:instrumentation* / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D003290:Convergence, Ocular / Q000502:physiology; D003626:Data Display; D004867:Equipment Design; D005099:Exotropia / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D005403:Fixation, Ocular / Q000502:physiology; D005500:Follow-Up Studies; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation*; D010364:Pattern Recognition, Visual / Q000502:physiology; D010775:Photic Stimulation; D010781:Photography / Q000295:instrumentation*; D012984:Software; D013285:Strabismus / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D013813:Therapy, Computer-Assisted / Q000295:instrumentation*; D014584:User-Computer Interface; D015357:Vision Disparity / Q000502:physiology*