title: The electronic visual acuity tester: testability in preschool children.
abstract: OBJECTIVE
  To evaluate the ability of preschool children to have their threshold visual acuity assessed using a standardized, computer-based letter test.
  
  
  METHODS
  Participants were 1195 3.5- to 5-year-old children enrolled in the Vision in Preschoolers Study. Monocular visual acuity was assessed by licensed eye care professionals (optometrists and pediatric ophthalmologists experimented in the examination of children), using the Electronic Visual Acuity tester, which uses the letters H, O, T, and V with a crowded surround.
  
  
  RESULTS
  Overall, 99.1% of children passed the training that consisted of identifying the letters H, O, T, and V by naming or matching the letters at 60 cm. Among those who passed the training, 99.6% completed the binocular pretest at 3 m, and 97.6% of those passing the training and the pretest completed monocular threshold visual acuity testing of each eye with the Electronic Visual Acuity tester. Testability increased with age for training (p = 0.03), pretesting (p = 0.04), and acuity testing (p = 0.07). Overall, 93.3% of 3.5-year-olds, 96.7% of 4-year-olds, and 98.8% of 5-year-olds completed training, pretesting, and monocular threshold acuity testing of each eye using standard letter optotypes.
  
  
  CONCLUSIONS
  Using the computer-based Electronic Visual Acuity system, nearly all 3.5- to 5-year-old children can complete monocular acuity testing of each eye.
authors.forename: Marjean Taylor
authors.initials: MT
authors.lastname: Kupl
authors.forename: Velma
authors.initials: V
authors.lastname: Dobson
authors.forename: Ellen
authors.initials: E
authors.lastname: Peskin
authors.forename: Graham
authors.initials: G
authors.lastname: Quinn
authors.forename: Paulette
authors.initials: P
authors.lastname: Schmidt
mesh_terms: D002675:Child, Preschool; D004581:Electronics; D006801:Humans; D014787:Vision Tests; D015349:Vision, Monocular; D014792:Visual Acuity