title: The importance of the phase transfer function to visual function and visual quality metrics.
abstract: OBJECTIVE
  To propose a vision quality metric that directly incorporates the phase transfer function.
  
  
  METHODS
  The process of retinal image formation from the pupil to the retina is presented to identify possible domains for calculating vision quality metrics. These domains are pupil plane metrics using ocular aberrations, and retinal plane metrics using the point spread function or optical transfer function. The importance of the phase transfer function to visual performance is demonstrated and a method is proposed for directly including phase in a vision quality metric based on ocular wavefront error.
  
  
  RESULTS
  A family of vision quality metrics is proposed, which directly incorporates the Stiles-Crawford effect, contrast sensitivity function, and the phase transfer function.
  
  
  CONCLUSIONS
  The phase transfer function is an important aspect of the quality of an image, and it may be directly included in metrics intended to quantify vision quality.
authors.affiliation: Sarver and Associates, Inc., Makanda, IL, USA. ejsarver@aol.com
authors.forename: Edwin J
authors.initials: EJ
authors.lastname: Sarver
authors.forename: Raymond A
authors.initials: RA
authors.lastname: Applegate
mesh_terms: D015350:Contrast Sensitivity; D019781:Corneal Topography; D005583:Fourier Analysis; D006801:Humans; D012030:Refractive Errors / Q000175:diagnosis*; D014787:Vision Tests / Q000379:methods*; D014785:Vision, Ocular; D014792:Visual Acuity