title: Visual performance of two simultaneous vision multifocal contact lenses.
abstract: OBJECTIVE
  To evaluate and compare the visual performance of two simultaneous vision multifocal contact lenses (CLs).
  
  
  METHODS
  In this cross-over study design 20 presbyopic subjects were fitted with two different simultaneous vision multifocal CLs (the PureVision Multifocal Low Add and Acuvue Oasys for Presbyopia) in random order. After 1 month, binocular distance visual acuity (BDVA) under photopic (85 cd/m(2)) and mesopic (3 cd/m(2)) conditions, binocular near visual acuity (BNVA), binocular distance contrast sensitivity function (CSF) under photopic and mesopic conditions, binocular near CSF and defocus curve were measured. Subjects were then refitted with the alternative correction and the procedure was repeated.
  
  
  RESULTS
  Mean BDVA under photopic conditions was similar for the Acuvue Oasys for Presbyopia and PureVision Multifocal Low Add: 0.01 ± 0.08 and 0.00 ± 0.08 logMAR, respectively (P = 0.45). Under mesopic conditions the values of BDVA were 0.20 ± 0.58 and 0.11 ± 0.09 logMAR, respectively (P = 0.005). Mean BNVA was 0.20 ± 0.05 and 0.15 ± 0.08 logMAR for the Acuvue Oasys and PureVision Low Add, respectively (P = 0.06). Binocular distance CSF testing revealed no statistically significant differences between lenses under photopic, mesopic or near conditions. Both lenses provided a comparable intermediate visual acuity.
  
  
  CONCLUSIONS
  Both simultaneous vision multifocal CLs provided adequate distance visual quality under photopic and mesopic conditions, and better visual acuity was provided under mesopic conditions for the Purevision lens. Both lenses provided adequate visual performance at intermediate distance, but the near visual acuity appears to be insufficient for early presbyopes who require a moderately demanding near visual quality.
authors.affiliation: Optometry Research Group, Optics Department, University of Valencia, Valencia, Spain. david.madrid@uv.es
authors.forename: David
authors.initials: D
authors.lastname: Madrid-Costa
authors.forename: Santiago
authors.initials: S
authors.lastname: García-Lázaro
authors.forename: César
authors.initials: C
authors.lastname: Albarrán-Diego
authors.forename: Teresa
authors.initials: T
authors.lastname: Ferrer-Blasco
authors.forename: Robert
authors.initials: R
authors.lastname: Montés-Micó
mesh_terms: D000328:Adult; D003261:Contact Lenses / Q000592:standards*; D015350:Contrast Sensitivity / Q000502:physiology; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011305:Presbyopia / Q000503:physiopathology / Q000628:therapy*; D015348:Vision, Binocular / Q000502:physiology; D014792:Visual Acuity / Q000502:physiology