title: Depth perception in random dot stereograms is not affected by changes in either vergence or accommodation.
abstract: OBJECTIVE
  To test the hypothesis that extraretinal cues related to vergence angle and lens accommodation are used to scale horizontal disparities for fixation distance.
  
  
  METHODS
  Depth perception of random dot stereograms was studied in 10 healthy adult subjects with normal visual acuity by modifying retinal disparity, fixation distance, vergence angle, and accommodation. Statistical analysis was used to compare the data.
  
  
  RESULTS
  Depth perception increased with fixation distance. The increment of depth perception persisted even when horizontal retinal disparity was kept constant. The magnitude of depth perception was independent of vergence angle. Depth perception did not vary with changes in accommodation.
  
  
  CONCLUSIONS
  Extraretinal cues related to vergence angle and accommodation seem to be not necessary to scale horizontal disparities for viewing distance.
authors.affiliation: Departamento de Fisiologia, Laboratorios de Neurociencia Ramón Dominguez, Santiago de Compostela, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Gonzalez
authors.forename: C
authors.initials: C
authors.lastname: Rivadulla
authors.forename: R
authors.initials: R
authors.lastname: Perez
authors.forename: C
authors.initials: C
authors.lastname: Cadarso
mesh_terms: D000065:Accommodation, Ocular / Q000502:physiology*; D000328:Adult; D003290:Convergence, Ocular / Q000502:physiology*; D003867:Depth Perception / Q000502:physiology*; D006801:Humans; D012016:Reference Values; D015357:Vision Disparity / Q000502:physiology; D014787:Vision Tests