title: Accommodative and binocular dysfunctions: prevalence in a randomised sample of university students.
abstract: BACKGROUND
  The aim was to analyse the prevalence of symptomatic accommodative and non-strabismic binocular dysfunctions in a randomised population of university subjects.
  
  
  METHODS
  A cross-sectional study was conducted with a randomised sample of 175 university students aged between 18 and 35 years. All subjects were given a visual examination in which their symptoms were recorded, as well as performing objective and subjective refractive examinations and accommodative and binocular tests. Each subject was tested for the presence of uncorrected refractive error. Accommodative dysfunctions (AD) and binocular dysfunctions (BD) were diagnosed according to the number of clinical signs associated with each disorder, considering the signs that could be associated with each dysfunction as fundamental or complementary. An accommodative or binocular dysfunction was diagnosed when the subjects met two conditions: presenting with any kind of visual symptom in their clinical history and presenting the fundamental sign associated with each dysfunction as well as two or more complementary signs. Those subjects who presented with only an uncorrected refractive error were considered within the group called refractive dysfunction (RD).
  
  
  RESULTS
  The overall prevalence of accommodative and/or binocular dysfunctions was 13.15 per cent and for refractive dysfunction it was 45.14 per cent. Accommodative dysfunctions were present in 2.29 per cent of the population, binocular dysfunctions were observed in eight per cent and accommodative dysfunctions together were found in 2.86 per cent of the university students. Within the accommodative and binocular disorders, the most prevalent dysfunctions were convergence insufficiency, with a prevalence of 3.43 per cent and convergence excess and accommodation excess, both with a prevalence of 2.29 per cent.
  
  
  CONCLUSIONS
  Binocular dysfunctions were more prevalent than accommodative dysfunctions or accommodative and binocular dysfunctions together in a randomised population of university students.
authors.affiliation: Departamento de Óptica, Farmacología y Anatomía, Universidad de Alicante, Alicante, Spain. ag.munoz@ua.es.
authors.forename: Ángel
authors.initials: Á
authors.lastname: García-Muñoz
authors.affiliation: Departamento de Óptica, Farmacología y Anatomía, Universidad de Alicante, Alicante, Spain.
authors.forename: Stela
authors.initials: S
authors.lastname: Carbonell-Bonete
authors.affiliation: Departamento de Óptica, Farmacología y Anatomía, Universidad de Alicante, Alicante, Spain.
authors.forename: Mario
authors.initials: M
authors.lastname: Cantó-Cerdán
authors.affiliation: Departamento de Óptica, Farmacología y Anatomía, Universidad de Alicante, Alicante, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Cacho-Martínez
mesh_terms: D000065:Accommodation, Ocular / Q000502:physiology*; D000293:Adolescent; D000328:Adult; D003430:Cross-Sectional Studies; D006801:Humans; D015995:Prevalence; D013334:Students; D014495:Universities; D014786:Vision Disorders / Q000453:epidemiology*; D015348:Vision, Binocular / Q000502:physiology*
keywords: accommodative dysfunctions; binocular dysfunctions; prevalence; randomised sample university students