title: Age-related changes in the human visual system and prevalence of refractive conditions in patients attending an eye clinic.
abstract: OBJECTIVE
  To retrospectively report the trends of change in several parameters of the human visual system over a wide age range in patients attending an eye clinic.
  
  
  METHODS
  University of Valencia, Valencia, Spain.
  
  
  METHODS
  The clinical records of 2654 patients were retrospectively reviewed, and the age, sex, spherocylindrical refraction, visual acuity, keratometry, and intraocular pressure were obtained. Descriptive values for each parameter and the correlations with age and between different parameters were calculated. Vectorial components of refraction, including blur, were also derived from clinical refractive data and then analyzed.
  
  
  RESULTS
  Several parameters changed significantly with age, particularly in patients in their sixties and older. An increase in the blur component was mainly associated with astigmatic progression and a trend toward against-the-rule orientation and had the highest correlation with total astigmatism (r= -0.319; P<.001) and visual acuity (r= -0.442; P<.001). Refractive conditions had the most homogeneous distribution in the first decade of life and the most heterogeneous distribution in the group between 61 years and 70 years.
  
  
  CONCLUSIONS
  Best corrected visual acuity began to decrease after the 50s, while changes in the blur component were not patent until the 60s to 70s. This could be explained by the poorer optical quality of the human eye in adulthood and elderly persons. Clinically, these changes could be attributed to changes in ocular astigmatism and have an impact on the best visual acuity achievable with optical compensation.
authors.affiliation: Human Vision Performance Research Group, Department of Optics, University of Valencia, Valencia, Spain.
authors.forename: Teresa
authors.initials: T
authors.lastname: Ferrer-Blasco
authors.forename: Jose Manuel
authors.initials: JM
authors.lastname: González-Méijome
authors.forename: Robert
authors.initials: R
authors.lastname: Montés-Micó
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007223:Infant; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012029:Refraction, Ocular / Q000502:physiology; D012030:Refractive Errors / Q000453:epidemiology*; D012189:Retrospective Studies; D014786:Vision Disorders / Q000453:epidemiology*; D014785:Vision, Ocular / Q000502:physiology; D014792:Visual Acuity / Q000502:physiology