In preschool, Ethan Wehse had trouble doing puzzles. By first grade, his teacher noticed him struggling to copy from the blackboard. Suspecting her son had attention-deficit hyperactivity disorder, Terrie Wehse of Stowe, VT, took him to see a neurologist, who found no evidence of ADHD.

At the end of first grade, the mother of another child on Ethan’s T-ball team noticed that he was having trouble drawing. Her daughter went to a pediatric optometrist, and she recommended to Terrie that Ethan do the same. An optometrist found that Ethan had poor depth perception. “Just because you have 20/20 vision doesn’t mean that you’re seeing properly,” says Terrie. “That was a huge lesson.”

In search of a diagnosis

Every year thousands of parents struggle to find out why their child is having trouble — or making trouble — in school, just as Terrie did. A third-grader who can’t see the chalkboard may be suspected of having a behavioral disorder like ADHD. A second-grader who can’t hear what the teacher is saying may be mistakenly identified as cognitively delayed.

“If a child can’t see or can’t hear, they’re not going to learn, and they’re not going to behave,” explains Dr. Charles Shubin, director of pediatrics at Mercy FamilyCare, a division of Family Health Centers in Baltimore.

Young children may simply be unaware that something is wrong. “Kids don’t realize that seeing double or letters slipping apart as they are reading is not normal,” says Dr. Larry Lampert, a behavioral optometrist from Boca Raton, Fla. This means vision and hearing problems can go undetected for years.

According to the National Commission on Vision and Health, some 25% of school-age children suffer from a vision problem. While the majority of states require some vision screening before a child enters school, only three — Kentucky, Illinois, and Missouri — mandate comprehensive exams using the latest screening methods.

Misdiagnosing misbehavior

The unawareness of the child combined with the misinformed assumptions of the teacher can lead to some miscarriages of classroom justice. In 2008 Lampert treated a 7-year-old girl who was ordered by her teacher to sit on a stool in the corner of the classroom because she wasn’t paying attention. It turned out the student wasn’t acting up: Severe farsightedness prevented her from seeing her work.

“Nothing was wrong with her other than she needed an eye exam,” Lampert says. “This was obviously missed in the screening.”

Even a child with 20/20 vision can suffer from convergence insufficiency, in which the eyes have trouble working together as a team, which can cause blurred vision, eye strain, double vision, or difficulty comprehending after short periods of reading. Or the child could have an “accommodation” problem, in which the eyes struggle to focus when rapidly going from near (the paper on the desk) to far (the blackboard) and back again.

The eye exam

A comprehensive eye exam includes evaluating visual acuity, ocular alignment, and depth perception, according to Mary Louise Collins, a pediatric ophthalmologist in Baltimore who is a spokesperson for the American Academy of Ophthalmology. An ophthalmologist also measures the refractive error with the pupils dilated and examines the structural health of the eye, including the retina and the optic nerve.

Not hearing versus not listening

Hearing problems can also be mistaken for a learning disability or behavioral problem. A student with even a mild form of hearing loss can miss 10 to 50% of a teacher’s voice, depending on the distance from the teacher and the background noise in the classroom, according to Anne Oyler, staff audiologist for the American Speech-Language-Hearing Association.

“In order to understand speech, you need to have really good access to all the sounds of speech,” explains Oyler. For instance, a student with high-frequency hearing loss might not be able to hear the so-called voiceless consonants, such as s, t, p, and f.

In the classroom, that student might look like he or she is daydreaming. “If a child cannot hear classroom instruction and they can’t follow along, they’re more likely to get bored and not pay attention, and that would result in a behavior problem,” says Oyler.

Studies suggest that on average 10% of school-age children in the United States suffer from some form of hearing loss, temporary or permanent.

Controversy over treatments

Parents should be forewarned that the line between learning disabilities and vision and hearing problems can be blurry. Moreover, clinicians differ widely in their views on how such problems should be treated. For instance, there is vehement professional disagreement between ophthalmologists and optometrists about the efficacy of vision therapy, which consists of eye exercises conducted under the supervision of an optometrist.

In an article in the August 2009 issue of the journal Pediatrics, the American Academy of Ophthalmology and the American Academy of Pediatrics released an update of their joint statement on learning disabilities, dyslexia, and vision, which sharply criticized the use of vision therapy for the treatment of dyslexia or LD. The American Optometric Association swiftly issued a rebuttal to the statement, charging that it misrepresented how vision therapy is used today as well as the scientific research about its effectiveness.

The debate rages on as ophthalmologists contend that such vision therapy is frequently misused, treating neurological problems as if they were ocular ones. “From an anatomic standpoint, it doesn’t make a lot of sense why doing eye exercises would help a learning disorder or a reading disorder,” says Collins with the American Academy of Ophthalmology.

Optometrists defend their therapy, dismissing criticism as so much professional bluster from the competition. Dr. Leonard Press, who chairs the Pediatrics and Binocular Vision Committee of the American Optometric Association, notes, “Eye surgeons say, ‘If vision therapy was worthwhile, don’t you think that we’d be doing it?'”