title: In vitro power profiles of daily disposable contact lenses.
abstract: OBJECTIVE
  To evaluate and compare the distribution of refractive power within the optic zone of different soft contact lenses and to investigate the effect of lens decentration on the power profiles.
  
  
  METHODS
  The Nimo TR1504 instrument was used to measure the optical power across different aperture diameters (from 1.5mm to 5.5mm in steps of 0.5mm) of four daily disposable contact lenses: DAILIES TOTAL1, Proclear 1-Day, SofLens daily disposable and 1-DAY ACUVUE MOIST. Measurements were performed using a wet cell. Power data were evaluated when contact lenses were in its centered position and after inducing different amounts of lens decentration (from 0.2mm to 1.0mm in steps of 0.2mm).
  
  
  RESULTS
  All contact lenses showed an increase - more negative - in lens power with distance from the lens center. The amount of change varied depending on the lens. It was about 10% of lens power for DAILIES TOTAL1 (-0.29diopters (D)), SofLens daily disposable (-0.36D), and Proclear 1-Day (-0.32D) whereas 1-DAY ACUVUE MOIST showed a percentage variation of 3.3% (-0.10D). After inducing a lens decentration up to 1mm, the power curves were shifted in the negative direction. However, the change obtained in lens power compared with well-centered position was always lower than a quarter of diopter both for all the lenses and aperture diameters.
  
  
  CONCLUSIONS
  Our results showed a variation of the refractive power from the lens center, becoming more negative toward the periphery, with a negligible effect of the decentration for all disposable contact lenses studied.
authors: Optometry Research Group, University of Valencia, Spain. lurdes.belda@uv.es
authors: Lurdes
authors: L
authors: Belda-Salmerón
authors: David
authors: D
authors: Madrid-Costa
authors: Teresa
authors: T
authors: Ferrer-Blasco
authors: Santiago
authors: S
authors: García-Lázaro
authors: Robert
authors: R
authors: Montés-Micó
mesh_terms: D003261:Contact Lenses / Q000145:classification*; D004209:Disposable Equipment / Q000145:classification*; D004867:Equipment Design; D019544:Equipment Failure Analysis
keywords: Back vertex power; Contact lens; Daily disposable contact lens; Deflectometry; Power profile