title: Change in dynamic visual acuity (DVA) by pupil dilation.
abstract: OBJECTIVE
  This study was conducted to assess dynamic visual acuity (DVA) under pupil dilation.
  
  
  BACKGROUND
  Pupil dilation may negatively affect driving performance.
  
  
  METHODS
  Thirty healthy young adults (mean age 29.4 years) with pupil dilation participated in this study as the Mydrin P group. In addition to them, 15 healthy young adults (mean age 28.5 years) without pupil dilation were enrolled as the control group. DVA was measured binocularly with free-head viewing at 0, 30, 60, 120, and 360 min after mydriatic drop instillation in both eyes. Pupil size was measured at each time.
  
  
  RESULTS
  In the Mydrin P group, DVA significantly improved at 30, 60, and 120 min (ANOVA; p < .01) but returned to the predilation level at 360 min (ANOVA; p = .61). Pupil size changed from 4.1 to 7.8 mm (ANOVA; p < .01) at 30 min after the instillation, and this level was maintained up to 120 min but returned to normal within 360 min. In the control group, DVA did not significantly change at all measured times (ANOVA; p > .9). DVA was significantly (p < .05) correlated with the pupil size at all measured times.
  
  
  CONCLUSIONS
  The improvement in DVA was related to the enlargement of the pupil. This study suggests that the pupil size is one factor that may affect DVA.
  
  
  CONCLUSIONS
  Potential applications of this study include useful information to assess the effect of pupil dilation on driving performance.
authors.affiliation: Department of Ophthalmology, Nara Medical University, Nara, Japan. tueda@naramed-u.ac.jp
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Ueda
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Nawa
authors.forename: Eiichi
authors.initials: E
authors.lastname: Yukawa
authors.forename: Futoshi
authors.initials: F
authors.lastname: Taketani
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Hara
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001334:Automobile Driving; D005260:Female; D006801:Humans; D008297:Male; D009184:Mydriatics / Q000494:pharmacology*; D011680:Pupil / Q000187:drug effects* / Q000502:physiology; D013997:Time Factors; D015348:Vision, Binocular; D014792:Visual Acuity / Q000187:drug effects / Q000502:physiology*
chemical_list: D009184:Mydriatics