title: Development of distant stereoacuity in visually normal children as measured by the Frisby-Davis distance stereotest.
abstract: OBJECTIVE
  To establish the range of normal distance stereoacuity and evaluate its development in visually normal children by using the Frisby-Davis distance stereotest (FD2).
  
  
  METHODS
  The distance stereoacuity of visually normal children aged less than 11 years and of adults was measured with FD2 using a standard testing protocol.
  
  
  RESULTS
  This study involved 94 visually normal children aged 36-131 months and 46 visually normal adults aged 20-49 years. The distance stereoacuity of the children aged 36-59 months was 40.61 (SD 9.823) seconds of arc; that of the children aged 60-119 months, 14.18 (8.152) seconds of arc; and that of the adults, 12.50 (4.802) seconds of arc. The FD2 distance stereoacuity of the children aged 36-59 months differed significantly from that of the older subjects (p = 0.000), and the FD2 distance stereoacuity of the children aged more than 59 months did not differ significantly from that of the adults (p = 0.813).
  
  
  CONCLUSIONS
  Distance stereoacuity reaches adult levels at approximately 5 years of age. These data of the age-related normal values could represent a reference frame for the comparison of data obtained for clinical populations.
authors.affiliation: Department of Ophthalmology, Kangnam St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: S W
authors.initials: SW
authors.lastname: Hong
authors.forename: S C
authors.initials: SC
authors.lastname: Park
mesh_terms: D000328:Adult; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D002985:Clinical Protocols; D004215:Distance Perception / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D014787:Vision Tests / Q000379:methods*; D014792:Visual Acuity / Q000502:physiology