title: Factors Associated with Visual Fatigue from Curved Monitor Use: A Prospective Study of Healthy Subjects.
abstract: OBJECTIVE
  To investigate the factors associated with visual fatigue using monitors with various radii of curvature.
  
  
  METHODS
  Twenty normal healthy adults (8 men, 12 women; mean age, 26.2 ± 2.5 years) prospectively watched five types of monitors including flat, 4000R, 3000R, 2000R, and 1000R curved monitors for 30 min. An experienced examiner measured the ophthalmological factors including near point of accommodation (NPA), near point of convergence (NPC), refraction, parameters during pupil response at light and saccadic movement just before and after the visual tasks. The questionnaires about subjective ocular symptoms were also investigated just before and after the visual tasks.
  
  
  RESULTS
  The NPA increased after the visual tasks with a flat monitor compared with the curved monitors, with the 1000R curved monitor showing the smallest change (p = 0.020). The NPC increased for every monitor after the visual tasks; the largest increase occurred with the flat monitor (p = 0.001). There was no difference in refractive error, pupil response, or saccadic movement in the comparison of before and after the visual tasks. Among the nine factors in the questionnaire, the score of "eye pain" was significantly higher for the flat monitor versus the 1000R curved monitor after the visual tasks (p = 0.034).
  
  
  CONCLUSIONS
  We identified NPA, NPC, and eye pain as factors associated with visual fatigue. Also, the curvature of the monitor was related to the visual fatigue.
authors.affiliation: Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Haeng Jin
authors.initials: HJ
authors.lastname: Lee
authors.affiliation: Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Republic of Korea.|Seoul Artificial Eye Center, Seoul National University Hospital Clinical Research Institute, Seoul, Republic of Korea.
authors.forename: Seong-Joon
authors.initials: SJ
authors.lastname: Kim
mesh_terms: D000065:Accommodation, Ocular; D000328:Adult; D001248:Asthenopia / Q000175:diagnosis*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014792:Visual Acuity; D055815:Young Adult