title: [The grating acuity of children in preschool age].
abstract: OBJECTIVE
  To study the developmental trend of the binocular grating acuity of preschool children.
  
  
  METHODS
  Binocular grating acuities in 599 children from 2 months to 72 months old (18 groups) were measured using the closed-circuit operant preferential looking system (COPLs). The children included in the investigation were required to be a normal term birth, development and normal eyes, and cycloplegic refraction error within specific limits. The system's reliabilities and measurable rates were also evaluated.
  
  
  RESULTS
  The difference of the vision acuities obtained by the same tester on different days has no statistic significance. The measurable rates reached 90% in most age groups. The grating acuity of the children included in the study developed rapidly during first year, and then it reached to a slower development period from 30 to 36-months, the grating acuity stabilized after 3 years old.
  
  
  CONCLUSIONS
  The COPL system is a practical devise to assess the grating visual acuity of infants and preschool children and it can be used to investigate the vision developmental trend including speed, age of its maturation and the top-acuity of the development.
authors.affiliation: Department of Ophthalmology, Second Hospital of Wenzhou Medical College, Wenzhou 325027, China. pshimg@wzhealth.com
authors.forename: Ming-guang
authors.initials: MG
authors.lastname: Shi
authors.forename: Li-qin
authors.initials: LQ
authors.lastname: Jiang
authors.forename: Chun
authors.initials: C
authors.lastname: Zhou
mesh_terms: D000550:Amblyopia / Q000175:diagnosis*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D015351:Vision Screening; D015348:Vision, Binocular / Q000502:physiology; D014792:Visual Acuity / Q000502:physiology*