title: The effects of induced oblique astigmatism on symptoms and reading performance while viewing a computer screen.
abstract: BACKGROUND
  Computer vision syndrome (CVS) is a complex of eye and vision problems related to computer use which has been reported in up to 90% of computer users. Ocular symptoms may include asthenopia, accommodative and vergence difficulties and dry eye. Previous studies have reported that uncorrected astigmatism may have a significant impact on symptoms of CVS. However, its effect on task performance is unclear.
  
  
  METHODS
  This study recorded symptoms after a 10 min period of reading from a computer monitor either through the habitual distance refractive correction or with a supplementary -1.00 or -2.00D oblique cylinder added over these lenses in 12 young, visually-normal subjects. Additionally, the distance correction condition was repeated to assess the repeatability of the symptom questionnaire. Subjects' reading speed and accuracy were monitored during the course of the 10 min trial.
  
  
  RESULTS
  There was no significant difference in reading rate or the number of errors between the three astigmatic conditions. However, a significant change in symptoms was reported with the median total symptom scores for the 0, 1 and 2D astigmatic conditions being 2.0, 6.5 and 40.0, respectively (p < 0.0001). Further, the repeatability coefficient of the total symptom score following the repeated zero astigmatism condition was ± 13.46.
  
  
  CONCLUSIONS
  The presence of induced astigmatism produced a significant increase in post-task symptoms but did not affect reading rate or the number of reading errors. The correction of small astigmatic refractive errors may be important in optimizing patient comfort during computer operation.
authors.affiliation: SUNY College of Optometry, New York, USA. mrosenfield@sunyopt.edu
authors.forename: Mark
authors.initials: M
authors.lastname: Rosenfield
authors.forename: Jennifer E
authors.initials: JE
authors.lastname: Hue
authors.forename: Rae R
authors.initials: RR
authors.lastname: Huang
authors.forename: Yuliya
authors.initials: Y
authors.lastname: Bababekova
mesh_terms: D000065:Accommodation, Ocular / Q000502:physiology; D000328:Adult; D001248:Asthenopia / Q000209:etiology / Q000503:physiopathology; D001251:Astigmatism / Q000150:complications* / Q000503:physiopathology / Q000628:therapy; D016288:Computer Terminals; D015352:Dry Eye Syndromes / Q000209:etiology / Q000503:physiopathology; D005139:Eyeglasses; D005260:Female; D006801:Humans; D008297:Male; D011932:Reading; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D013577:Syndrome; D014786:Vision Disorders / Q000209:etiology* / Q000503:physiopathology; D055815:Young Adult