CNN: If your child gets recurring headaches and you think they might need glasses, you may be mistaken – a new study says children’s headaches are rarely triggered by vision problems.

The study, presented Monday at the American Academy of Ophthalmology’s annual meeting, was conducted by researchers at the ophthalmology clinic of Albany Medical Center in New York. They evaluated medical records of nearly 160 children under the age of 18 who were being seen at the clinic for frequent headaches.

Researchers compared the exams of children with headaches to their earlier vision exams and other medical records. In 75% of the children, the vision test results were the same. No significant link was found between the headaches and a need for glasses – even if the headaches happened when the child is doing a visual task like homework.

“We hope our study will help reassure parents that in most cases their children’s headaches are not related to vision or eye problems, and that most headaches will clear up in time,” said Dr. Zachary Roth, who led the research team. “The information should also be useful to family doctors and pediatricians in caring for children and parents who have this common health concern.”

Researchers found in most cases, the children’s headaches resolved over a period of time regardless of whether the child got a new prescription for glasses or not. And those who did get new glasses were no more likely to have their headaches get better.

It’s highly unusual to find something wrong with the eyes when a child complains of headaches, says Dr. Daniel Neely, a professor of ophthalmology at Indiana University who specializes in pediatrics and the chairman of theAmerican Association for Pediatric Ophthalmology and Strabismus’ vision screening committee.

“The study is consistent with everyone’s clinical practice around the country. If the child has headaches the first stop should be their primary care doctor, and they will assess whether or not a comprehensive eye exam would be indicated.”

According to Neely, vision screenings – whether someone just measures the vision with an eye chart or with a vision screening device (camera-type devices called photo screeners) – should be part of a pediatric well-child visit .

“Some of them are very good about doing it and some of them are not very good about doing it, but the recommendation is that it should be done every year or two,” he says. ” … What we don’t recommend is that everyone get a comprehensive eye doctor eye exam unless they fail a screening or unless there is something in their family history that puts them at increased risk.”

Neely says if vision screening is not being offered as part of the well-child visits, ask for it – sooner rather than later.

“The reason that there’s a time factor on these screenings is because of a condition called amblyopia,” he says. “Young children less than age 7 are neurologically immature and if you have something significant affecting their vision, their brain will actually stop using the eye or both eyes and that becomes permanent loss of vision if not detected and treated. So the younger you identify them, the more easily you can treat them.”

Amblyopia, or lazy eye, is very common in children and is responsible for more vision loss than all the other causes combined, according to AAPOS. It happens when the eye sends blurry images to the brain, confusing it and causing the brain to learn to ignore images from the weak eye.

And Neely says as children get older they are less likely to respond to corrective treatment. “So if you detect something at age 10 that was serious, it would be too late. And that, again, is why we want the pediatrician doing this, because by the time the kid gets to school that window of opportunity is closing. So a vision screening by the school nurse in first grade might be too late.”

Most pediatricians will do some variation of the screening at every visit, Neely says, but AAPOS recommends children have a documented vision measurement by age 5.