In Tami’s story, her daughter Lilly passed the vision screening that their school system required for kindergarten, but was found to have amblyopia at an eye exam at an ophthalmologists (read the whole story) . As I was looking in to this, I was surprised to learn that this isn’t all that uncommon. Children can and do pass the quick vision screenings at their doctors or at school, when in fact, they do have vision problems that need to be treated. In the United States, most states require some vision screening before a child starts school (though 16 states have no requirement at all), only 3 states require a comprehensive eye exam. I’d love to hear from readers in other countries about whether they have any vision screenings or exams that are required of children before they start school.
What’s the difference between a vision screening and a comprehensive eye exam? A comprehensive eye exam is performed by an opthalmologist or optometrist and includes a visual acuity test using one eye, and then the other, cover testing, and then dilating drops and retinoscopy (if you’re reading this because your child wears glasses, this would be the very familiar eye exam). The screenings, on the other hand, vary from place to place, but most typically involve reading an eye chart or vision acuity cards, though some use refractors that measure the refractive error of the eye without dilating the eye first. Screenings may be done by pediatricians, school nurses, technicians or trained lay persons. There is no question that the full comprehensive eye exam is necessary to get the complete picture of a someone’s vision needs. The question is whether a screening can identify kids with vision issues and get them to an eye exam to figure out exactly what treatment is needed.
The Report of the National Commission of Vision and Health on Children’s Vision that was released this summer does a nice job of compiling and explaining studies that have been done to compare vision screenings to vision exams (the report is here, start on page 9 for the section on screenings and exams). Vision in Preschoolers, or VIP, is one such study, conducted in 2001-2004, by the National Eye Institute, which compared 11 vision screening tests to see which were the most accurate. The three best tests still missed more than 30% of kids with vision problems (though they did identify 90% of children with the most severe vision problems).
At least one study cited in the report found that the additional cost of having all children go through a comprehensive eye exam is easily offset by the increase in the number of children whose amblyopia could be detected earlier and treated successfully, compared with the numbers detected and treated with a vision screening program (full text of that study is here).
I know that I’m preaching to the choir here at Little Four Eyes, but please encourage friends and family to have their children’s vision checked out at a full eye exam, rather than relying on vision screenings. Programs such as InfantSEE (at infantSEE.org) provide exams at no cost for infants, and many insurance programs cover comprehensive eye exams once a year or once every two years.