title: Effect of optical defocus on performance of dogs involved in field trial competition.
abstract: OBJECTIVE
  To measure the effect of induced myopia on field trial performance in dogs.
  
  
  METHODS
  7 Labrador Retrievers and 1 Chesapeake Bay Retriever trained in field trial competition.
  
  
  METHODS
  Dogs were commanded to retrieve targets at 137.2 m (150 yards). Each dog participated in 3 trials while their eyes were fitted with 0- (plano), +1.50-, or +3.00-diopter (D) contact lenses, applied in random order. Retrieval times were measured objectively, and dog performances were evaluated subjectively by masked judges.
  
  
  RESULTS
  Retrieval times were significantly faster with plano lenses than with +1.50- or +3.00-D lenses, but there were no significant differences in times between +1.50- and +3.00-D lenses. Masked judges assigned the best performance scores to dogs with plano lenses and the lowest scores to dogs fitted with +3.00-D lenses.
  
  
  CONCLUSIONS
  Even mild myopic defocusing had a significant negative impact on both the subjective and objective assessments of dogs' performances. Dogs with demanding visual tasks or signs of visual deterioration should be evaluated retinoscopically to determine the refractive state because they may have ametropia.
authors.affiliation: Department of Clinical Sciences, Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Rehovot, Israel.
authors.forename: Ron
authors.initials: R
authors.lastname: Ofri
authors.forename: Steven R
authors.initials: SR
authors.lastname: Hollingsworth
authors.forename: Allyson
authors.initials: A
authors.lastname: Groth
authors.forename: Monica J
authors.initials: MJ
authors.lastname: Motta
authors.forename: John H
authors.initials: JH
authors.lastname: Doval
authors.forename: Philip H
authors.initials: PH
authors.lastname: Kass
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Murphy
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D004285:Dogs / Q000502:physiology*; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology*; D008297:Male; D013177:Sports; D014792:Visual Acuity / Q000502:physiology*