title: The effect of optical devices and repeated trials on the velocity of saccadic eye movements.
abstract: OBJECTIVE
  The purpose of this prospective study was to analyze the effect of glasses and contact lenses on the latency and velocity of visually evoked saccadic eye movements.
  
  
  METHODS
  A saccadic test was performed 10 times on 20 emmetropic controls (Group A) and 20 ametropic test subjects with myopia (Group B) who were using glasses (Subgroup Bg) or contact lenses (Subgroup Bc).
  
  
  RESULTS
  No training or fatigue effect on either latency or eye velocity was registered. Regardless of visual acuity (Group A or B) or of the optical device used (Subgroup Bg or Bc), no significant intergroup difference in latency could ultimately be established. Subgroup Bc showed a significantly slower eye velocity than Group A. Regardless of the optical device used, subjects with a higher degree of myopia (> 6 D) showed a lower eye velocity than the Group A controls. Additionally, saccadic velocity was lower in this subgroup ( > 6 D) in subjects using contact lenses than in those using glasses.
  
  
  CONCLUSIONS
  These results demonstrate that optical devices have an influence on the electronystagmographical analyses of the vestibulo-ocular reflex that must be taken into consideration, particularly in scientific investigations.
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, University of Münster, Münster, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Müller
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Stoll
authors.forename: Frank
authors.initials: F
authors.lastname: Schmäl
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003261:Contact Lenses; D005139:Eyeglasses; D005260:Female; D006801:Humans; D008297:Male; D009216:Myopia / Q000503:physiopathology; D011446:Prospective Studies; D011930:Reaction Time; D012027:Reflex, Vestibulo-Ocular; D012438:Saccades / Q000502:physiology