title: Is binocular contrast sensitivity at distance compromised with multifocal soft contact lenses used to correct presbyopia?
abstract: OBJECTIVE
  The purpose of this investigation was to determine whether new experimental multifocal optical designs incorporating diffractive/refractive optics for correction of presbyopia in a soft contact lens would compromise binocular contrast sensitivity at distance while achieving 20/20 binocular visual acuity at near.
  
  
  METHODS
  Thirty presbyopic volunteers were fitted with Acuvue Bifocal soft lenses, two (FO1 and 3B1) experimental diffractive/refractive multifocal soft lenses separately and in combination as a pair and soft spherical lenses. Visual performance was evaluated via binocular contrast sensitivity and binocular distance high- and low-contrast visual acuity after 1 week of lens wear.
  
  
  RESULTS
  The experimental lenses FO1 and the combination FO1/3B1 performed as well for binocular contrast sensitivity, binocular distance high-contrast visual acuity, and binocular distance low-contrast visual acuity as the habitual presbyopic correction and the spherical soft distance correction. A strong correlation (r = 0.73 and 0.53, respectively) was found between binocular contrast sensitivity and binocular distance low-contrast visual acuity with experimental FO1 and FO1/3B1 lenses. However, the correlation (r = 0.37 and 0.60, respectively) between binocular contrast sensitivity and binocular distance high- and low-contrast visual acuity with FO1 was weaker than that with the combination FO1/3B1 lenses. Subjective responses support the objective data.
  
  
  CONCLUSIONS
  The data show that experimental FO1 lens and the experimental combination of the FO1/3B1 lenses can be prescribed to not compromise distance binocular contrast sensitivity.
authors.affiliation: Borish Center for Opthalmic Research, School of Optometry, Indiana University, Bloomington, Indiana, USA.
authors.forename: P Sarita
authors.initials: PS
authors.lastname: Soni
authors.forename: Roshani
authors.initials: R
authors.lastname: Patel
authors.forename: R Scott
authors.initials: RS
authors.lastname: Carlson
mesh_terms: D000328:Adult; D000368:Aged; D001334:Automobile Driving; D003263:Contact Lenses, Hydrophilic / Q000009:adverse effects*; D015350:Contrast Sensitivity; D004215:Distance Perception; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D011305:Presbyopia / Q000503:physiopathology* / Q000628:therapy*; D015348:Vision, Binocular; D014792:Visual Acuity