title: Effects of ocular dominance on binocular summation after monocular reading adds.
abstract: OBJECTIVE
  To investigate the relationship between ocular dominance and binocular summation with monocular reading adds.
  
  
  METHODS
  Department of Orthoptics and Visual Science, School of Allied Health Sciences, Kitasato University, Sagamihara, Kanagawa, Japan.
  
  
  METHODS
  Contrast sensitivities were measured by having subjects view contrast charts at spatial frequencies of 1.5, 3.0, 6.0, 12.0, and 18.0 cycles per degree after the addition of positive spherical lenses that ranged from +1.0 to +3.0 diopters (D). Through the use of a balance technique, the test group was quantitatively divided into 12 weak and 8 strong ocular dominance subjects on the basis of binocular rivalry. In study 1, binocular contrast sensitivity was measured in the weak and strong ocular dominances by adding a positive spherical lens in front of 1 eye, whereas the other eye was fixed at a corrected distance.
  
  
  RESULTS
  In study 1, the binocular summation was observed only after adding positive spherical lenses in the nondominant eye. The differences in binocular contrast sensitivity that occurred after adding a positive spherical lens in the dominant eye versus that seen in the nondominant eye were statistically significant in the strong ocular dominance subjects who had +1.5 D and +2.0 D defocuses (P<.05; analysis of variance).
  
  
  CONCLUSIONS
  Binocular summation was effectively maintained with reading adds in the nondominant eye and was significantly influenced by the magnitude of ocular dominance. Evaluating binocular summation after monocular reading adds seems to be a good method to evaluate adaptability to monovision.
authors.affiliation: Department of Orthoptics and Visual Science, School of Allied Health Sciences, Kitasato University, Yokohama, Japan. thanda@kitasato-u.ac.jp
authors.forename: Tomoya
authors.initials: T
authors.lastname: Handa
authors.forename: Kimiya
authors.initials: K
authors.lastname: Shimizu
authors.forename: Kazuo
authors.initials: K
authors.lastname: Mukuno
authors.forename: Takushi
authors.initials: T
authors.lastname: Kawamorita
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Uozato
mesh_terms: D000328:Adult; D015350:Contrast Sensitivity / Q000502:physiology*; D023882:Dominance, Ocular / Q000502:physiology*; D005139:Eyeglasses; D006801:Humans; D011932:Reading; D015357:Vision Disparity / Q000502:physiology*; D015348:Vision, Binocular; D015349:Vision, Monocular