title: A study of static, kinetic, and dynamic visual acuity in 102 Japanese professional baseball players.
abstract: BACKGROUND
  It seemed that visual functions might have some effects on the performance of baseball players. We measured static, kinetic, and dynamic visual acuity (SVA, KVA, and DVA, respectively) of Japanese professional baseball players to ascertain whether there would be any difference in SVA, KVA, and DVA among player groups stratified according to their performance level.
  
  
  METHODS
  The subjects were 102 male professional baseball players with a mean age of 26 years who were members of a Japanese professional baseball club from 2000 to 2009. They were stratified into three groups according to their performance level: A (players who were on the roster of the top-level team all the time throughout the study period), B (players who were on the roster of the top-level team sometimes but not all the time), and C (players who were never on the roster of the top-level team). They were interviewed for the use of corrective visual aids, and examined for SVA, KVA, and DVA. The measurements of these parameters were compared among groups A, B, and C. We also investigated and analyzed the association of KVA or DVA with player position (pitchers or fielders) and with hand dominance for batting. KVA was compared between the pitchers and the fielders because they each require different playing skills. DVA was compared between the right-handed and the left-handed batters.
  
  
  RESULTS
  There was no statistically significant difference among groups A, B, and C. There was a statistically significant difference in KVA between the pitchers and the fielders (t-test; P < 0.05) There was no statistically significant difference in DVA between the right-handed and the left-handed batters.
  
  
  CONCLUSIONS
  There was no significant difference in the examined visual functions among player groups with different performance levels.
authors.affiliation: Hoshina Eye Clinic, Nishinomiya, Japan.
authors.forename: Kohji
authors.initials: K
authors.lastname: Hoshina
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Tagami
authors.forename: Osamu
authors.initials: O
authors.lastname: Mimura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Edagawa
authors.forename: Masao
authors.initials: M
authors.lastname: Matsubara
authors.forename: Teiichi
authors.initials: T
authors.lastname: Nakayama
keywords: Japanese professional baseball players; dynamic visual acuity; kinetic visual acuity; static visual acuity