title: The visual function of professional baseball players.
abstract: OBJECTIVE
  To measure the visual acuity, stereoacuity, and contrast sensitivity of professional baseball players.
  
  
  METHODS
  Three hundred eighty-seven professional baseball players underwent several tests of visual function including distance visual acuity. Stereoacuity was evaluated at near by the Randot test and at distance by both contour and random dot targets. Distance stereoacuity was also tested under timed and untimed conditions. Contrast sensitivity was evaluated by the Vision Contrast Test System, Contrast Sensitivity Viewer, and Binocular Visual Acuity Tester.
  
  
  RESULTS
  Visual acuity (measured with players' regular distance correction) in 774 eyes ranged from 20/8.89 to 20/100. Near stereoacuity ranged from 23 to 37 seconds of arc, mean untimed distance contour stereoacuity from 55 to 35 seconds of arc, and mean untimed distance random dot stereoacuity from 98 to 76 seconds of arc. The results under timed conditions were 86 to 65 seconds of arc (timed distance contour stereoacuity) and 104 to 83 seconds of arc (timed distance random dot stereoacuity). Statistically significant differences were found between major and minor league players on tests of untimed distance contour and random dot stereopsis, and on contrast sensitivity testing with the 3.0- and 6.0-cpd gratings using the Contrast Sensitivity Viewer.
  
  
  CONCLUSIONS
  Professional baseball players have excellent visual skills. Mean visual acuity, distance stereoacuity, and contrast sensitivity are significantly better than those of the general population.
authors.affiliation: Jules Stein Eye Institute, UCLA, USA. danlaby@ibm.net
authors.forename: D M
authors.initials: DM
authors.lastname: Laby
authors.forename: A L
authors.initials: AL
authors.lastname: Rosenbaum
authors.forename: D G
authors.initials: DG
authors.lastname: Kirschen
authors.forename: J L
authors.initials: JL
authors.lastname: Davidson
authors.forename: L J
authors.initials: LJ
authors.lastname: Rosenbaum
authors.forename: C
authors.initials: C
authors.lastname: Strasser
authors.forename: M F
authors.initials: MF
authors.lastname: Mellman
mesh_terms: D001484:Baseball; D015350:Contrast Sensitivity / Q000502:physiology*; D003867:Depth Perception / Q000502:physiology*; D006801:Humans; D008297:Male; D014787:Vision Tests; D014785:Vision, Ocular / Q000502:physiology*; D014792:Visual Acuity / Q000502:physiology*