Measurement of the validity of a preschool vision screening program

Am J Public Health. 1999 Feb;89(2):193-8. doi: 10.2105/ajph.89.2.193.


Objectives: The validity (sensitivity and specificity) of a preschool vision screening program was measured over a 3-year period to determine how well strabismus and significant refractive errors could be detected.

Methods: Public health nurses were trained to administer tests of visual acuity, stereoacuity, and ocular alignment. Failure on any test, visual acuity of 6/9 or less, stereoacuity of less than 100 seconds of arc, or an apparent misalignment of the eyes resulted in referral to an eye care practitioner. An age-matched control was also referred. Analysis of practitioner reports used predefined study-based criteria for ocular abnormalities.

Results: More than 1100 children were screened each year. The annually calculated prevalence of vision problems ranged between 10.5% and 13.8%. The estimated sensitivity varied from 60.4% to 70.9% (specificity, 69.6% to 79.9%). The yield indicated that a very high percentage of children with vision problems were identified for the first time.

Conclusions: The validity of this screening is comparable to that of other school screenings. The limitations are predictable. Consideration should be given to replacing visual acuity tests with a rapid, objective measure of refractive error and ocular alignment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Case-Control Studies
  • Child, Preschool
  • Female
  • Humans
  • Male
  • Ontario
  • Public Health Nursing / education
  • Referral and Consultation / statistics & numerical data
  • Refractive Errors / diagnosis*
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Strabismus / diagnosis*
  • Vision Screening / methods*
  • Visual Acuity