title: Visual function of police officers who have undergone refractive surgery.
abstract: BACKGROUND
  The visual acuity and contrast sensitivity of police recruits and officers was evaluated in both normal and dim illumination conditions to determine whether officers who have had refractive surgery have compromised night vision.
  
  
  METHODS
  The control group consisted of 76 officers and recruits who have not had refractive surgery and the refractive surgery group consisted of 22 officers and recruits who had refractive surgery. Visual acuity and contrast sensitivity were measured under both room illumination and dim illumination. The room illumination test series included high contrast acuity, low contrast acuity and Pelli-Robson contrast sensitivity. The dim illumination test series included high contrast acuity, low contrast acuity, Pelli-Robson contrast sensitivity, license plate number acuity (with and without glare) and the Mesotest.
  
  
  RESULTS
  The general findings were that the refractive surgery group had lower acuity scores on low contrast targets in both room and dim light levels along with a reduction in the Mesotest scores with a glare source compared to the control group.
  
  
  CONCLUSIONS
  Although refractive surgery police recruits and officers had reduced performance on some vision tests, these reductions were small and it is unlikely that their performance on vision related tasks would be compromised, on average. The major concern is the small number of refractive surgery candidates whose results were well outside the range of the non-surgical candidates. Their vision may be unacceptable for policing.
authors.affiliation: School of Optometry, University of Waterloo, Waterloo, Ontario, Canada. jhovis@uwaterloo.ca
authors.forename: Jeffery K
authors.initials: JK
authors.lastname: Hovis
authors.forename: Shankaran
authors.initials: S
authors.lastname: Ramaswamy
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D048988:Corneal Surgery, Laser / Q000009:adverse effects*; D006801:Humans; D009755:Night Blindness / Q000209:etiology*; D009864:Ontario; D016495:Police; D014787:Vision Tests / Q000379:methods*; D014792:Visual Acuity; D014938:Work Capacity Evaluation