title: Computer vision syndrome among computer office workers in a developing country: an evaluation of prevalence and risk factors.
abstract: BACKGROUND
  Computer vision syndrome (CVS) is a group of visual symptoms experienced in relation to the use of computers. Nearly 60 million people suffer from CVS globally, resulting in reduced productivity at work and reduced quality of life of the computer worker. The present study aims to describe the prevalence of CVS and its associated factors among a nationally-representative sample of Sri Lankan computer workers.
  
  
  METHODS
  Two thousand five hundred computer office workers were invited for the study from all nine provinces of Sri Lanka between May and December 2009. A self-administered questionnaire was used to collect socio-demographic data, symptoms of CVS and its associated factors. A binary logistic regression analysis was performed in all patients with 'presence of CVS' as the dichotomous dependent variable and age, gender, duration of occupation, daily computer usage, pre-existing eye disease, not using a visual display terminal (VDT) filter, adjusting brightness of screen, use of contact lenses, angle of gaze and ergonomic practices knowledge as the continuous/dichotomous independent variables. A similar binary logistic regression analysis was performed in all patients with 'severity of CVS' as the dichotomous dependent variable and other continuous/dichotomous independent variables.
  
  
  RESULTS
  Sample size was 2210 (response rate-88.4%). Mean age was 30.8 ± 8.1 years and 50.8% of the sample were males. The 1-year prevalence of CVS in the study population was 67.4%. Female gender (OR: 1.28), duration of occupation (OR: 1.07), daily computer usage (1.10), pre-existing eye disease (OR: 4.49), not using a VDT filter (OR: 1.02), use of contact lenses (OR: 3.21) and ergonomics practices knowledge (OR: 1.24) all were associated with significantly presence of CVS. The duration of occupation (OR: 1.04) and presence of pre-existing eye disease (OR: 1.54) were significantly associated with the presence of 'severe CVS'.
  
  
  CONCLUSIONS
  Sri Lankan computer workers had a high prevalence of CVS. Female gender, longer duration of occupation, higher daily computer usage, pre-existing eye disease, not using a VDT filter, use of contact lenses and higher ergonomics practices knowledge all were associated with significantly with the presence of CVS. The factors associated with the severity of CVS were the duration of occupation and presence of pre-existing eye disease.
authors.affiliation: Department of Pharmacology, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka. priyanga.ranasinghe@gmail.com.
authors.forename: P
authors.initials: P
authors.lastname: Ranasinghe
authors.affiliation: Department of Pharmacology, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka. wsevwandi@hotmail.com.
authors.forename: W S
authors.initials: WS
authors.lastname: Wathurapatha
authors.affiliation: Ministry of Health Care and Nutrition, Colombo, Sri Lanka. yashas2004@yahoo.com.
authors.forename: Y S
authors.initials: YS
authors.lastname: Perera
authors.affiliation: Ministry of Health Care and Nutrition, Colombo, Sri Lanka. dilu_lama@yahoo.com.
authors.forename: D A
authors.initials: DA
authors.lastname: Lamabadusuriya
authors.affiliation: Ministry of Health Care and Nutrition, Colombo, Sri Lanka. supunkulatunga@yahoo.com.
authors.forename: S
authors.initials: S
authors.lastname: Kulatunga
authors.affiliation: Ministry of Health Care and Nutrition, Colombo, Sri Lanka. naveenjay@gmail.com.
authors.forename: N
authors.initials: N
authors.lastname: Jayawardana
authors.affiliation: Department of Clinical Medicine, Faculty of Medicine, University of Colombo, Colombo, Sri Lanka. prasad.katulanda@yahoo.com.
authors.forename: P
authors.initials: P
authors.lastname: Katulanda
mesh_terms: D000293:Adolescent; D000328:Adult; D001248:Asthenopia / Q000453:epidemiology* / Q000503:physiopathology; D015352:Dry Eye Syndromes / Q000453:epidemiology* / Q000503:physiopathology; D006804:Ergonomics; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000453:epidemiology* / Q000503:physiopathology; D015995:Prevalence; D018401:Sample Size; D012720:Severity of Illness Index; D013188:Sri Lanka / Q000453:epidemiology; D011795:Surveys and Questionnaires; D014584:User-Computer Interface