From artificial organs to robotic surgery, modern medical science has vastly improved in the past few decades. Why then, despite all these technological advances, are most pediatricians and public schools still using vision tests developed 148 years ago? In a world where surgeons can preserve the vision of patients with ocular tumors, relying on a vision test where kids simply cover an eye and read a string of letters seems a little archaic. But despite its simplicity, the commonly used Snellen Eye Chart is very accurate— assuming the test subject is old enough to understand what’s being asked of him.
“The standard school vision test is generally fine for older children who understand the process,” says David Hunter, MD, PhD, Ophthalmologist-in-Chief at Children’s Hospital Boston’s Department of Ophthalmology. “But it isn’t perfect. When used in schools it doesn’t always detect farsightedness (trouble focusing up close), or those who have problems with convergence (aiming both eyes at a near target).”
Hunter suggests children who are having unexplained difficulties in school visit an ophthalmologist or optometrist, even if they’ve already passed a school or pediatrician administered test. “You don’t want to rely solely on a school eye test to rule out vision problems as a factor in your child’s school struggles,” he says.
Some symptoms parents should be mindful of if their child is experiencing academic difficulties include:
- Excessive squinting
- Trouble reading and/or a resistance to school work
- A tilting of the head when focusing
- Headaches after short periods of reading or focusing
- Holding books or papers too close – or too far away from – the face
When it comes to preschool children, the stakes are even higher. “It’s much trickier to test vision in preschoolers because in a lot of cases the kids can’t yet express themselves fully, or don’t quite know what’s being asked of them,” Hunter says.
Current school and pediatric vision exams for young children are largely based on a child’s ability to answer questions about what they see during the test. But many toddlers and preschoolers have yet to develop the ability to clearly describe their field of vision or comprehend the eye test questions, which can skewer their answers and test results. Consequently, some children who “pass” pediatrician or school vision exams actually have medical eye problems which will go untreated. Amblyopia, or “lazy eye,” is an example. With Amblyopia vision is lost because the brain is not paying attention to the image coming in from one eye, the longer it goes untreated the harder t can become to correct. “If amblyopia is treated early, before school age – it is often possible to recover normal vision,” Hunter says. “But if the diagnosis and treatment are delayed, it may be too late to get vision back, and the child will have a lifetime of poor vision in one eye.”
But researchers at Children’s are looking to change that. The hospital is currently testing an eye scanning prototype that digitally identifies misalignments in a child’s eyes, without relying on input from the children themselves. Though still in the trial stage, researchers have already successfully tested children as young as 2 years-old, an almost impossible feat for many current tests. Early identification leads to early treatment, which often means vision irregularities like amblyopia can be fixed while there is still time.