title: Prevalence of impairment of visual function in European drivers.
abstract: OBJECTIVE
  This study aimed to investigate the prevalence of impairment of visual function amongst European drivers.
  
  
  METHODS
  A total of 2422 drivers from five European countries underwent a battery of visual function tests, including tests for visual acuity (VA), visual field (VF), contrast sensitivity, straylight (glare sensitivity) and useful field of view (UFOV). Subjects belonged to the following age categories: 45-54 years; 55-64 years; 65-74 years, and ≥ 75 years. A group of subjects aged 20-30 years served as a reference group. Results were compared with current standards for the visual function of drivers in the EU.
  
  
  RESULTS
  Visual acuity in 0.5% of the younger group and 5.3% of the eldest group was below the standard required for driving. Visual acuity after proper refraction adhered to the standard in the majority of cases. Visual field results were below standard or questionable in 2.7% and 2.4%, respectively, of subjects in the eldest group. In this eldest group, impaired contrast sensitivity was present in 6.3%, increased glare sensitivity in 29.5% and impaired UFOV in 21.6% of subjects, but, as there are no standards for these criteria, the exact level of prevalence depends on the definition of impairment.
  
  
  CONCLUSIONS
  Prevalences of impairment of visual functions that are not included in current standards (particularly contrast sensitivity and glare sensitivity) are much higher than prevalences of functions that are included (VA and VF).
authors.affiliation: Department of Ophthalmology, Vrije University Medical Centre, Amsterdam, The Netherlands. vanRijn@vumc.nl
authors.forename: Laurentius J
authors.initials: LJ
authors.lastname: van Rijn
authors.forename: Christian
authors.initials: C
authors.lastname: Nischler
authors.forename: Ralph
authors.initials: R
authors.lastname: Michael
authors.forename: Christian
authors.initials: C
authors.lastname: Heine
authors.forename: Tanja
authors.initials: T
authors.lastname: Coeckelbergh
authors.forename: Helmut
authors.initials: H
authors.lastname: Wilhelm
authors.forename: Günther
authors.initials: G
authors.lastname: Grabner
authors.forename: Rafael I
authors.initials: RI
authors.lastname: Barraquer
authors.forename: Thomas J T P
authors.initials: TJ
authors.lastname: van den Berg
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology; D001334:Automobile Driving; D015350:Contrast Sensitivity / Q000502:physiology*; D005062:European Union / Q000706:statistics & numerical data; D005260:Female; D019466:Glare; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D014786:Vision Disorders / Q000453:epidemiology*; D014787:Vision Tests; D014792:Visual Acuity / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology*; D019987:Persons with Visual Disabilities / Q000706:statistics & numerical data*; D055815:Young Adult