title: Visual comparison of multifocal contact lens to monovision.
abstract: OBJECTIVE
  To compare visual function with the Bausch & Lomb PureVision multifocal contact lens to monovision with PureVision single vision contact lenses.
  
  
  METHODS
  Twenty presbyopic subjects were fitted with either the PureVision multifocal contact lens or monovision with PureVision single vision lenses. After a 1-month trial, the following assessments of visual function were made: (a) distance, intermediate, and near visual acuity (VA); (b) reading ability; (c) distance and near contrast sensitivity function (CSF); (d) near range of clear vision; (e) stereoacuity; and (f) subjective evaluation of near vision ability with a standardized questionnaire. Subjects were then refitted with the alternative correction and the procedure was repeated. All measurements were compared between the two corrections, whereas the "low addition" multifocal lens was also compared with the "high addition" alternative.
  
  
  RESULTS
  Distance and near VA were significantly better with monovision than with the multifocal option (p < 0.05). Intermediate VA (p = 0.13) was similar with both corrections, whereas there was also no significant difference in distance and near CSF (p = 0.29 on both occasions). Reading speeds (p = 0.48) and the critical print size (p = 0.90) were not significantly different between the two contact lens corrections, but stereoacuity (p < 0.01) and the near range of clear vision (p < 0.05) were significantly better with the multifocal option than with monovision. Subjective assessment of near ability was similar for both types of contact lens (p = 0.52). The high addition multifocal lens produced significantly poorer distance and near CSF, near VA, and critical print size compared with the low addition alternative.
  
  
  CONCLUSIONS
  Monovision performed better than a center-near aspheric simultaneous vision multifocal contact lens of the same material for distance and near VA only. The multifocal option provides better stereoacuity and near range of clear vision, with little differences in CSF, so a better balance of real-world visual function may be achieved due to minimal binocular disruption.
authors.affiliation: Ophthalmic Research Group, School of Life and Health Sciences, Aston University, Birmingham, United Kingdom.
authors.forename: Navneet
authors.initials: N
authors.lastname: Gupta
authors.forename: Shehzad A
authors.initials: SA
authors.lastname: Naroo
authors.forename: James S
authors.initials: JS
authors.lastname: Wolffsohn
mesh_terms: D000368:Aged; D003262:Contact Lenses, Extended-Wear; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology / Q000628:therapy*; D016896:Treatment Outcome; D015349:Vision, Monocular / Q000502:physiology*; D014792:Visual Acuity