title: Abnormal tear dynamics and symptoms of eyestrain in operators of visual display terminals.
abstract: OBJECTIVE
  To clarify the relation between the prevalence of dry eye syndrome and subjective symptoms of asthenopia in visual display terminal (VDT) operators.
  
  
  METHODS
  722 VDT workers (242 subject workers with symptoms of asthenopia and 480 controls without such symptoms) without obvious organic ocular diseases received an ophthalmological examination consisting of refractometry and a tear function (phenol red thread) test.
  
  
  RESULTS
  More than 30% of symptomatic workers were found to meet the criteria of dry eye, and the odds ratio compared with the controls was 4.61 (p < 0.001). This odds ratio was significantly greater than that obtained for refractive errors (2.31).
  
  
  CONCLUSIONS
  Although this cross sectional study could not prove that dry eyes are the cause of asthenopia, the profound association of dry eyes with symptoms of asthenopia could be verified. It would be useful to carry out tear function tests in workers with symptoms of asthenopia.
authors.affiliation: Department of Hygiene, Occupational and Environmental Medicine, Kanazawa Medical University, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Nakaishi
authors.forename: Y
authors.initials: Y
authors.lastname: Yamada
mesh_terms: D000328:Adult; D001248:Asthenopia / Q000150:complications* / Q000503:physiopathology; D004396:Coloring Agents; D016288:Computer Terminals; D003430:Cross-Sectional Studies; D015352:Dry Eye Syndromes / Q000150:complications*; D005260:Female; D006801:Humans; D008297:Male; D009784:Occupational Diseases / Q000150:complications* / Q000503:physiopathology; D010637:Phenolsulfonphthalein; D012030:Refractive Errors / Q000150:complications; D013666:Tears / Q000378:metabolism
chemical_list: D004396:Coloring Agents; D010637:Phenolsulfonphthalein