title: Cycloplegic refractions in healthy children aged 1 through 48 months.
abstract: OBJECTIVE
  To provide a description of refractive errors in healthy, term-born children, aged 1 through 48 months, and to test the hypotheses that spherical equivalent becomes significantly less hyperopic and less variable with increasing age.
  
  
  METHODS
  Following a prospective, cross-sectional design, cycloplegic retinoscopy was used to measure the refractive error in both eyes of 514 healthy, term-born children in 12 age groups. Three hundred were aged 12 months or younger. Spherical equivalent and cylindrical power and axis were analyzed as a function of age. Prediction limits for spherical equivalent were calculated.
  
  
  RESULTS
  Spherical equivalents of right and left eyes did not differ at any age. Hyperopia declined significantly with increasing age. The variability in spherical equivalent also decreased significantly with age. Cylindrical error of 1 diopter or more was found in 25% of the children; the proportion with astigmatism was highest in infancy and then waned. Myopia and anisometropia were rare, occurring in 3% and 1% of the sample, respectively.
  
  
  CONCLUSIONS
  Significant declines in hyperopia and variability of spherical equivalent appear to be features of emmetropization. The normal prediction limits provide guidelines against which data from individual patients can be compared.
authors.affiliation: Department of Ophthalmology, Children's Hospital Boston, 300 Longwood Ave, Boston, MA 02115, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Mayer
authors.forename: R M
authors.initials: RM
authors.lastname: Hansen
authors.forename: B D
authors.initials: BD
authors.lastname: Moore
authors.forename: S
authors.initials: S
authors.lastname: Kim
authors.forename: A B
authors.initials: AB
authors.lastname: Fulton
mesh_terms: D017677:Age Distribution; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003519:Cyclopentolate / Q000008:administration & dosage*; D005123:Eye / Q000254:growth & development; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008404:Massachusetts / Q000453:epidemiology; D009184:Mydriatics / Q000008:administration & dosage*; D011446:Prospective Studies; D011680:Pupil / Q000187:drug effects*; D012016:Reference Values; D012029:Refraction, Ocular; D012030:Refractive Errors / Q000175:diagnosis / Q000453:epidemiology*
chemical_list: D009184:Mydriatics; D003519:Cyclopentolate