title: Age-related changes in accommodative dynamics from preschool to adulthood.
abstract: OBJECTIVE
  To study variations in dynamic measures of accommodation and disaccommodation with age in subjects ranging from preschool to adulthood.
  
  
  METHODS
  Accommodative responses to a step stimulus cartoon movie alternating from distance to near were recorded with a dynamic infrared photorefractor. Subjects viewed at least three stimulus cycles of far and near for four near stimulus demands (2, 3, 4, and 5 D). Latencies, peak velocities, and the magnitude of accommodative microfluctuations were calculated from the responses and compared in 41 subjects from 3 to 38 years of age.
  
  
  RESULTS
  Mean accommodative and disaccommodative latencies decreased linearly with age. The magnitude of accommodative microfluctuations during sustained near accommodation had a significant quadratic relationship to age, with subjects in the first decade of life having the largest fluctuations and subjects in the third decade of life having the smallest for all stimulus demands. Accommodative peak velocities were fastest in subjects in the first two decades of life, compared with subjects in the third and fourth decades; however, disaccommodative peak velocities showed no significant age differences.
  
  
  CONCLUSIONS
  Age-related changes in dynamics occur in accommodative and disaccommodative latencies, accommodative peak velocities, and accommodative microfluctuations, all of which decrease with increasing age from preschool to adulthood. Disaccommodative peak velocities showed no change with age.
authors.affiliation: College of Optometry, University of Houston, Houston, Texas 77204-2020, USA. handerson@optometry.uh.edu
authors.forename: Heather A
authors.initials: HA
authors.lastname: Anderson
authors.forename: Adrian
authors.initials: A
authors.lastname: Glasser
authors.forename: Ruth E
authors.initials: RE
authors.lastname: Manny
authors.forename: Karla K
authors.initials: KK
authors.lastname: Stuebing
mesh_terms: D000065:Accommodation, Ocular / Q000502:physiology*; D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000375:Aging / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D006801:Humans; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
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