title: Three-dimensional display-induced transient myopia and the difference in myopic shift between crossed and uncrossed disparities.
abstract: OBJECTIVE
  To investigate whether three-dimensional (3D) images cause nearwork-induced transient myopia (NITM) more than 2D images and whether there is any difference between 3D images with crossed and uncrossed disparities in the development of NITM.
  
  
  METHODS
  Twenty-five volunteers, enrolled in this study, watched 2D and 3D movies and read 3D texts with crossed and uncrossed disparities for 2 to 3 hours with spectacle correction. The viewing distance was 50 to 70 cm. The refractive error was measured before and after each visual task. If there was a myopic shift after a task, the refractive error was measured at 3-minute intervals until it was resolved. The changes in the refractive error and the amount of NITM were evaluated and compared.
  
  
  RESULTS
  The mean age of volunteers was 27.8 ± 2.87 years, and the mean refractive error before the visual tasks was -4.19 ± 2.87 diopters (D). Thirteen subjects (52%) showed NITM after watching a 2D movie, whereas 20 subjects (80%) had NITM after a 3D movie (P = 0.037). The mean extent of NITM was 0.36 ± 0.27 D after watching a 3D movie and 0.10 ± 0.28 D after a 2D movie (P = 0.002). The 3D text with crossed disparity significantly induced NITM (P < 0.001), but that with uncrossed disparity did not. There was a tendency for the NITM to persist longer after subjects watched a 3D movie than after a 2D movie.
  
  
  CONCLUSIONS
  Viewing 3D images with crossed disparity induced a greater degree of NITM than 2D images. These results suggest that the greater NITM induced by 3D images may have a greater effect on the development and progression of permanent myopia.
authors: Department of Ophthalmology, Korea University College of Medicine, Seoul, Republic of Korea.
authors: Young-Woo
authors: YW
authors: Suh
authors: Jaeryung
authors: J
authors: Oh
authors: Hyo-Myung
authors: HM
authors: Kim
authors: Yoonae A
authors: YA
authors: Cho
authors: Jong-Suk
authors: JS
authors: Song
mesh_terms: D000065:Accommodation, Ocular / Q000502:physiology*; D000328:Adult; D003867:Depth Perception / Q000502:physiology*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000009:adverse effects*; D008297:Male; D009216:Myopia / Q000209:etiology* / Q000503:physiopathology; D010775:Photic Stimulation / Q000009:adverse effects*; D012030:Refractive Errors; D015348:Vision, Binocular / Q000502:physiology