title: Effect of pupil size on visual acuity in a laboratory model of pseudophakic monovision.
abstract: OBJECTIVE
  To investigate the effect of pupil size on visual acuity in pseudophakic monovision.
  
  
  METHODS
  For the simulation, a modified Liou-Brennan model eye was used. The model eye was designed to include a centered optical system, corneal asphericity, an iris pupil, a Stiles-Crawford effect, an intraocular lens, and chromatic aberration. Calculation of the modulation transfer function (MTF) was performed with ZEMAX software. Visual acuity was estimated from the MTF and the retinal threshold curve. The sizes of the entrance pupil were 2.0, 2.5, 3.0, and 4.0 mm.
  
  
  RESULTS
  Decreasing pupil diameter and increasing myopia progressively improved near visual acuity. For an entrance pupil size of 2.5 mm and a refractive error of -1.50 diopters, the logMAR value (Snellen; metric) in the non-dominant eye at 40 cm was 0.06 (20/23; 6/6.9).
  
  
  CONCLUSIONS
  Knowledge of the patient's pupil diameter at near fixation can assist surgeons in determining the optimum degree of myopia for successful monovision.
authors.affiliation: Department of Orthoptics and Visual Science, Kitasato University School of Allied Health Sciences, 1-15-1 Kitasato, Sagamihara, Japan. kawa2008@kitasato-u.ac.jp
authors.forename: Takushi
authors.initials: T
authors.lastname: Kawamorita
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Uozato
authors.forename: Tomoya
authors.initials: T
authors.lastname: Handa
authors.forename: Misae
authors.initials: M
authors.lastname: Ito
authors.forename: Kimiya
authors.initials: K
authors.lastname: Shimizu
mesh_terms: D006801:Humans; D008954:Models, Biological; D009216:Myopia / Q000503:physiopathology; D019591:Pseudophakia / Q000503:physiopathology*; D011680:Pupil / Q000502:physiology*; D015349:Vision, Monocular / Q000502:physiology*; D014792:Visual Acuity / Q000502:physiology*