title: Myopia, genetics, and ambient lighting at night in a UK sample.
abstract: BACKGROUND
  It has been reported that exposure to artificial lighting at night during the first 2 years of life was very strongly associated with subsequent myopia development.
  
  
  METHODS
  The strength of this association was tested in a UK sample for the first time. The study population comprised 122 university students.
  
  
  RESULTS
  Myopia occurred with approximately equal frequency in those who slept with and without light exposure at night. In contrast, two largely genetic factors, parental myopia and race, were both significantly associated with myopia development, as has been found previously.
  
  
  CONCLUSIONS
  This study provides further support for the view that night-time light exposure during infancy is not a major risk factor for myopia development in most population groups. In a subset of this cohort for which spectacle prescriptions were available for both parents (49 trios), the heritability of ocular refraction was estimated to be 0.31.
authors.affiliation: Cardiff University, Cathays Park, Cardiff, UK. guggenheim@cf.ac.uk
authors.forename: J A
authors.initials: JA
authors.lastname: Guggenheim
authors.forename: C
authors.initials: C
authors.lastname: Hill
authors.forename: T-F
authors.initials: TF
authors.lastname: Yam
mesh_terms: D000328:Adult; D001208:Asia / Q000208:ethnology; D005260:Female; D006801:Humans; D008029:Lighting / Q000009:adverse effects*; D008297:Male; D009216:Myopia / Q000453:epidemiology / Q000209:etiology* / Q000235:genetics; D010290:Parents; D012029:Refraction, Ocular / Q000235:genetics; D017678:Sex Distribution; D006113:United Kingdom / Q000453:epidemiology / Q000208:ethnology