Vision Screening Tools that are Age Appropriate and Evidence Based

Academic research suggests that 1 child in 10 to 20 will have vision problems that can lead to permanent vision impairment if those disorders are not detected and treated early. Common early childhood vision disorders include amblyopia (lazy eye), strabismus (misaligned eyes), and abnormal hyperopia (farsightedness), myopia (nearsightedness), and astigmatism that can lead to amblyopia. Vision screening is a cost-effective method for identifying children who would benefit from further vision care.

Fortunately, many vision screening tools are available. Unfortunately, many are inappropriate for use with young children or lack scientific evidence. Consequently, visual acuity may be over- or underestimated.

Selecting Age-Appropriate Tools

Age-appropriate vision screening tools helps to ensure children can participate in vision screening. Academic research suggests that children who are unable to participate in vision screening tests are more likely to have vision disorders than children who pass vision screening.

By the time children reach the age of 3, most are able to participate in visual acuity screening using an eye chart. Those too young for a visual acuity chart or unable to cooperate in eye chart screening can be screened using an autorefractor, or a photoscreener, all of which have been researched and tested.

When selecting an eye chart for preschoolers, the National Academy of Sciences-National Research Council (1980) recommends choosing tests that:

  • Include the same number of optotypes (symbols or letter) per line

  • Have equal legibility on any given line

  • Have appropriate spacing between optotypes on a line (equal to the width of the optotype)

  • Have appropriate spacing between lines (space between 2 lines is equal to the next line down)

  • Are standardized.


Appropriate eye charts for preschoolers from a joint Policy Statement of the American Academy of Pediatrics, American Association of Certified Orthoptists, American Association for Pediatric Ophthalmology and Strabismus, and the American Academy of Ophthalmology include:


Using Evidence-Based Screening Tools

Screening tools that have been subjected to academic research, rigorous testing, comparison studies, and peer-reviewed analyses are said to be evidence-based, and, therefore, include the best available research known to enhance outcomes.

Facilities establishing a vision screening program would benefit in understanding which vision screening protocols and tools are both age appropriate and evidence based.

Children entering school need to be healthy and ready to learn. Effective preschool vision screening programs offer children the opportunity to succeed.

By P. Kay Nottingham Chaplin, Ed.D., Vision Screening Consultant for School Health Corporation; Director - Early Vision Screening Initiatives for The Good-Lite Company

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