title: Contrast is enhanced by yellow lenses because of selective reduction of short-wavelength light.
abstract: OBJECTIVE
  Although many studies have shown a subjective preference for yellow lenses, there has been little success in determining the clinical nature of this benefit.
  
  
  METHODS
  Contrast sensitivity, color vision, accommodative-convergence, and visual acuity were measured in a group of 20 young subjects along with subjective rating of their perception through clear control lenses (380-nm cut-off), yellow lenses (450-nm cut-off), dark yellow lenses (511-nm cut-off), and orange lenses (527-nm cut-off).
  
  
  RESULTS
  A systematic detriment to color vision was found to occur with increasing cut-off wavelength of the yellow lenses (p < 0.001) and this was significantly correlated to subjective ratings of color (r = -0.66) and brightness (r = -0.34). Perceived brightness significantly improved for the yellow (450-nm cut-off) lens only (p < 0.001). Although tinted lenses reduced contrast sensitivity to a white on black grating, there was a significant improvement in low to midrange spatial frequencies when measured using a white-on-blue grating.
  
  
  CONCLUSIONS
  The detriment in color vision caused by yellow-colored lenses enhances contrast when viewing bright objects against a blue-based background, such as the sky. Contrast of overlying objects is enhanced is due to the selective reduction of short-wavelength light by the yellow lenses.
authors.affiliation: Clinic Research Unit, Victorian College of Optometry, University of Melbourne, Australia. j.s.w.wolffsohn@aston.ac.uk
authors.forename: J S
authors.initials: JS
authors.lastname: Wolffsohn
authors.forename: A L
authors.initials: AL
authors.lastname: Cochrane
authors.forename: H
authors.initials: H
authors.lastname: Khoo
authors.forename: Y
authors.initials: Y
authors.lastname: Yoshimitsu
authors.forename: S
authors.initials: S
authors.lastname: Wu
mesh_terms: D000065:Accommodation, Ocular / Q000502:physiology*; D000221:Adaptation, Ocular / Q000502:physiology; D000328:Adult; D003118:Color Perception / Q000502:physiology*; D015350:Contrast Sensitivity; D005139:Eyeglasses; D005374:Filtration; D006801:Humans; D008027:Light; D014792:Visual Acuity / Q000502:physiology