title: Effect of Age and Glaucoma on the Detection of Darks and Lights.
abstract: OBJECTIVE
  We have shown previously that normal observers detect dark targets faster and more accurately than light targets, when presented in noisy backgrounds. We investigated how these differences in detection time and accuracy are affected by age and ganglion cell pathology associated with glaucoma.
  
  
  METHODS
  We asked 21 glaucoma patients, 21 age-similar controls, and 5 young control observers to report as fast as possible the number of 1 to 3 light or dark targets. The targets were positioned at random in a binary noise background, within the central 30° of the visual field.
  
  
  RESULTS
  We replicate previous findings that darks are detected faster and more accurately than lights. We extend these findings by demonstrating that differences in detection of darks and lights are found reliably across different ages and in observers with glaucoma. We show that differences in detection time increase at a rate of approximately 55 msec/dB at early stages of glaucoma and then remain constant at later stages at approximately 800 msec. In normal subjects, differences in detection time increase with age at a rate of approximately 8 msec/y. We also demonstrate that the accuracy to detect lights and darks is significantly correlated with the severity of glaucoma and that the mean detection time is significantly longer for subjects with glaucoma than age-similar controls.
  
  
  CONCLUSIONS
  We conclude that differences in detection of darks and lights can be demonstrated over a wide range of ages, and asymmetries in dark/light detection increase with age and early stages of glaucoma.
authors.affiliation: Department of Biological and Visual Sciences State University of New York, College of Optometry, New York, New York, United States.
authors.forename: Linxi
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Department of Biological and Visual Sciences State University of New York, College of Optometry, New York, New York, United States.
authors.forename: Caroline
authors.initials: C
authors.lastname: Sendek
authors.affiliation: School of Cognitive Sciences, Institute for Research in Fundamental Sciences, Tehran, Iran.
authors.forename: Vandad
authors.initials: V
authors.lastname: Davoodnia
authors.affiliation: School of Cognitive Sciences, Institute for Research in Fundamental Sciences, Tehran, Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Lashgari
authors.affiliation: Department of Biological and Visual Sciences State University of New York, College of Optometry, New York, New York, United States.
authors.forename: Mitchell W
authors.initials: MW
authors.lastname: Dul
authors.affiliation: Department of Biological and Visual Sciences State University of New York, College of Optometry, New York, New York, United States.
authors.forename: Qasim
authors.initials: Q
authors.lastname: Zaidi
authors.affiliation: Department of Biological and Visual Sciences State University of New York, College of Optometry, New York, New York, United States.
authors.forename: Jose-Manuel
authors.initials: JM
authors.lastname: Alonso
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D003624:Darkness; D005260:Female; D005901:Glaucoma / Q000503:physiopathology*; D005902:Glaucoma, Open-Angle / Q000503:physiopathology; D006801:Humans; D008027:Light; D008297:Male; D008875:Middle Aged; D014796:Visual Perception / Q000502:physiology*