Pitfalls in vision testing of children

  • Inadequate test environment: Testing in a room with poor lighting or disturbances can lead to inaccurate results.
  • Incorrect test distance: Failure to maintain the appropriate test distance can distort the results and lead to false positive or negative results.
  • Forked selection of vision chart: that are not age appropriate or using charts with unfamiliar symbols may result in unreliable results.
  • Lack of cooperation: Children may not fully understand the testing process or may not cooperate, leading to inaccurate measurements.
  • Failure to correct for refractive errors: Failure to take into account refractive errors such as nearsightedness or farsightedness can result in misdiagnosis or underestimation of visual impairment.
  • Faulty test of both eyes independently: Screening both eyes independently is essential to identify unilateral vision problems that may otherwise go unnoticed.
  • Relying solely on screening tests: Screening tests should be followed up with comprehensive eye exams by an eye care professional to confirm results and identify any underlying problems.

Two out of three children with poor vision are not detected during routine checks with the Danish vision chart from 1934.

Many young children have vision problems and should have glasses, but this is not detected by tests, according to Politiken. Kindergarten children have their eyes checked annually by the doctor, while school children are tested by the health nurse. Even so, many children with impaired vision avoid being detected, shows a study with almost 500 children aged four to seven.

A major reason is that the most widespread vision chart in Denmark, the Østerberg chart from 1934, is not effective enough, believes Lisbeth Sandfeld, senior physician at Roskilde Hospital's eye department. The Østerberg chart, which has a swan at the top, is no longer used in other countries. It detects only about half of children with vision problems when used correctly, but in routine checks only one in three children is detected.

A newer chart based on the LogMAR principle, on the other hand, can detect 85 percent of children with vision problems. This chart uses line drawings instead of filled-in symbols, making it easier for children with farsightedness to distinguish.

Poor vision can lead to difficulty concentrating and learning difficulties. The president of the health nurses, Susanne Rank Lücke, is calling on municipalities to replace the Østerberg chart. The Danish Health Authority plans to change the guidelines and is already recommending LogMAR charts to municipalities.