It's one of the most basic things in education: seeing the board. Research has shown, over and over again, that if you can't see, you're going to have an awfully hard time in school. And yet too often this simple issue gets overlooked.

Just this year, research showed that children with a significant vision problem during the pre-school years perform significantly worse on tests of early literacy. And that poor performance early on affects their reading scores when they reach the third grade, says Kira Baldonado, director of the National Center for Children's Vision and Eye Health.

Her organization is out with a new report today that looks at children's vision screening across the country. We pulled the numbers and created a state-by-state breakdown — and a look at who those vision tests are reaching.

The Report

Most educators and parents know it's important to identify vision problems for children, but there just hasn't been a national consensus and unification around the approach, says Kira Baldonado.

"A vision screening that a child might get in California will look different from a vision screening that a child might get in Ohio," she says.

She points to differences in frequency — some states might screen just the early grades, kindergarten or first or second grade. Other states might do it throughout the school year, every year.

And of course, Baldonado points out, the requirements themselves may or may not have teeth.

Screening Early

There are only 15 states that require vision screening for preschool-aged children — the time experts say is critical for identifying vision problems that can cause permanent blindness or vision impairments for life.

"You're kind of time-limited," says Baldonado, with "the most successful outcomes you can get by the age of 7."

Knowing you've seen a child too late is very frustrating, says Millicent Peterseim, a pediatric ophthalmologist and the chair of the vision screening committee for the American Association of Pediatric Ophthalmology and Strabismus.

"We see those at age 8 or 9 when it's too late to treat them," she says. "They say, 'Oh, I thought everybody had one good eye and one bad eye' and your heart is crushed because if you caught them at age 3 or 4, you could have gotten back that vision, but it's too late."

But screening early doesn't mean states and schools should stop screening later.

"We like to make sure that every child has their vision checked every year," says Peterseim. Children's eyes change as they grow. If a student received glasses in first grade, they may have a completely different prescription in third grade.

So What Is The School's Role?

Schools still play an important part in making sure vision screenings happen.

For families that don't seek regular medical care, or are unsure of the medical system, schools can be a place they trust, where people already know their child, says Baldonado. Schools can also make sure kids are connected to care by providing information on where to receive a full eye exam or on organizations that provide free glasses.

That can be a source of kids falling through the cracks, says Peterseim. "Kids get picked up at the screening, but for whatever reason — and there are many, many reasons that children don't follow through — they don't get an exam."

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