title: A nationwide population-based survey on visual acuity, near vision, and self-reported visual function in the adult population in Finland.
abstract: OBJECTIVE
  To estimate the prevalence rates of habitual visual acuity (VA) levels and visual impairment in Finland and to assess their correlation with self-reported visual function.
  
  
  METHODS
  Cross-sectional population-based study.
  
  
  METHODS
  Subjects were selected randomly from the Finnish population aged 30 years or older. Of 7979 eligible people, 7393 (93%) were interviewed, 6771 (85%) were examined, and 6663 (84%) had distance VA assessed.
  
  
  METHODS
  Participants underwent a home interview and a comprehensive examination including measuring binocular VA for distance and for near with the participants' current spectacles, if any.
  
  
  METHODS
  The level of VA for distance and for near with current spectacle correction. The self-reported capability to read newsprint and television text and the ability to move about without being restricted by reduced vision.
  
  
  RESULTS
  The prevalence of good to moderate VA for distance (VA> or =0.5 [> or =20/40]) measured with current spectacles was 95.9%, and 87.4% had a VA level of 0.8 (20/25) or better. The prevalence of habitual visual impairment (VA< or =0.25 [< or =20/80]) was 1.6%, and 0.5% were blind (VA<0.1 [<20/200]). The prevalence of visual impairment increased significantly with age (P<0.001), especially in the age group of 65 to 74 years and upward. There was no gender difference in VA for distance, but decreased near vision (VA< or =0.25 [< or =20/80]) was significantly more common in men than in women (P<0.01). By applying the imputated numbers of visually impaired and blind participants to the Finnish population (approximately 3 million aged 30 years or older), there were approximately 65000 (2.1%) visually impaired and 17000 (0.6%) blind adult persons in the country in 2000. The correlation between self-reported visual ability and measured visual function was moderate but statistically significant (r = 0.27-0.40; P<0.0001). The proportion of people with reading difficulties or who were unable to read newsprint has decreased 7% during the last 2 decades.
  
  
  CONCLUSIONS
  Functional visual impairment increased with age especially in the age group of 65 to 74 years and upward and was as prevalent in women as in men. The prevalence of people with reading difficulties has decreased considerably since 1980.
authors.affiliation: Department of Health and Functional Capacity, National Public Health Institute, Helsinki, Finland.
authors.forename: Arja
authors.initials: A
authors.lastname: Laitinen
authors.forename: Seppo
authors.initials: S
authors.lastname: Koskinen
authors.forename: Tommi
authors.initials: T
authors.lastname: Härkänen
authors.forename: Antti
authors.initials: A
authors.lastname: Reunanen
authors.forename: Leila
authors.initials: L
authors.lastname: Laatikainen
authors.forename: Arpo
authors.initials: A
authors.lastname: Aromaa
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology; D003430:Cross-Sectional Studies; D005139:Eyeglasses; D005260:Female; D005387:Finland / Q000453:epidemiology; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012650:Self Disclosure; D017678:Sex Distribution; D014786:Vision Disorders / Q000453:epidemiology* / Q000503:physiopathology / Q000628:therapy; D015348:Vision, Binocular / Q000502:physiology; D014792:Visual Acuity / Q000502:physiology; D019987:Persons with Visual Disabilities / Q000706:statistics & numerical data*