Spelling Struggles: When Vision Plays a Role

Your child studies the spelling list on Wednesday, gets every word right on Thursday, and misses half of them on Friday. Parents in our Coconut Creek, Boynton Beach and West Palm Beach offices describe this pattern often, and it is confusing precisely because the effort is clearly there.

Here is the honest answer we give: spelling is first and foremost a language skill. Vision is one contributor among several. It is worth checking, but it is not the explanation for most spelling difficulty.

Key takeaways

• Spelling rests mainly on language: hearing sounds in words, matching them to letters, and building stored knowledge of how real words are spelled.
• Vision problems do not cause dyslexia or a spelling disorder. Professional bodies in pediatrics and ophthalmology are explicit about this.
• Visual-motor integration is measurably related to school performance, including teachers’ spelling ratings. That is an association, not a proven cause.
• Uncomfortable focusing or eye teaming can make near work harder than it needs to be. Office-based therapy does relieve the symptoms of convergence insufficiency (CITT, 2008), but the largest trial of that therapy found no reading benefit over placebo (CITT-ART, 2019).
• The right first step is usually structured spelling instruction plus a comprehensive vision evaluation to rule vision in or out.

What spelling actually is

To spell a word, a child has to break it into sounds, match each sound to letters, and then check the result against what they have stored about how that particular word looks. One longitudinal twin study followed 750 twin pairs in the United States and Australia and 230 twin pairs in Norway and Sweden from kindergarten into second grade. Phonological awareness, the ability to hear and play with the sounds inside words, was tied far more closely to spelling than rapid naming speed was: at the end of first grade, phonological awareness accounted for about five times as much variance in spelling as rapid naming speed did (Furnes & Samuelsson, 2011). The same authors are careful to add that reading and spelling scores were highly stable from year to year, which left relatively little variance for either predictor to explain. Sound comes first, but no single skill accounts for spelling.

Sound is also not the whole story. English is full of words that cannot be spelled by sound alone, so children build orthographic knowledge (how letter patterns work) and morphemic knowledge (roots, prefixes, endings) alongside it. Looking at samples of children’s independent writing between ages 5 and 8, one analysis argues that these three kinds of knowledge have to develop together, and that leaning predominantly on synthetic phonics can leave long-term spelling difficulty for children who do not pick up letter patterns on their own (McMurray, 2020). That paper considers writing samples rather than running a controlled trial, but it matches what teachers describe to us.

Where vision fits in

Vision does not generate the spelling. It supplies the visual information the language system works with, and it carries the written output onto the page.

Visual-motor integration

Visual-motor integration is the ability to copy what you see with your hand. Among 191 children in kindergarten through third grade, Beery VMI scores tracked with teachers’ spelling ratings for the 98 second- and third-graders who were rated on spelling (p = 0.0118) - a relationship, not a demonstrated cause (Kulp, 1999). Our post on perceptual skills and child development walks through the rest of that research and how these skills are tested.

Visual-spatial organization on the page

In a small study, 19 children with low visual-motor integration and 18 children with normal scores copied a written passage and also copied and solved math problems. The low-VMI group made more errors overall. Spacing errors of letters and words showed up more often on the writing task, and alignment of numbers and organization of math problems on the math task (Barnhardt et al., 2005). With only 37 children in total, that is a lead worth knowing rather than a settled finding. Still, a word crammed together or split apart can read as misspelled even when every letter is right, which overlaps with the handwriting and math difficulties families ask us about.

Letter reversals, and what eye movements can tell you

Parents often ask whether a child who writes b for d has an eye problem. In our clinical experience, reversals are common in the first years of writing and, on their own, rarely point to the eyes. What the evidence adds is that dyslexia is a language-based disorder, and that children with dyslexia or related learning disabilities have the same visual function and ocular health as children without them (Handler & Fierson, 2011). We wrote separately about whether letter reversals always mean dyslexia.

It is worth being equally careful about reading too much into eye movements. Decades of research show that how long the eyes rest on a word, and whether they jump back to reread it, reflect the language processing going on underneath from moment to moment (Rayner, 1998). Untidy eye movements during reading can be a sign of the reading difficulty as easily as a cause of it.

Comfort at reading and writing distance

Focusing, eye teaming and tracking decide whether near work is comfortable. In a survey of 825 Austrian schoolchildren referred for reading and writing difficulties, accommodative amplitude and facility were lower, vergence facility was reduced and the near point of convergence was receded compared with 328 controls (Dusek et al., 2010). That was retrospective data from a single specialist practice, and every child in the referred group was there because someone had already noticed a difficulty, so it describes a referred group rather than children in general.

Discomfort also shows up in how school work goes. Parents of 212 children with symptomatic convergence insufficiency rated them higher on a survey of school-related problem behaviors, including avoidance, difficulty finishing work and inattention, than parents of 49 children with normal eye teaming, and that difference held even among the children whose parents did not report ADHD (Rouse et al., 2009). That is a parent questionnaire at a single point in time. It tells us the two travel together, not that one causes the other.

What the research does and does not support

We want you to have the full picture, not the flattering half.

Neither the pediatric-ophthalmology position nor the optometric one presents vision care as a treatment for spelling. The 2009 joint statement from pediatrics and ophthalmology puts it bluntly: vision problems can interfere with learning, but they do not cause dyslexia, and the statement does not back eye exercises, behavioral vision therapy or tinted lenses as a treatment for a learning disability (AAP et al., 2009). Optometry’s joint policy statement puts more weight on vision as a contributing obstacle to be treated within a team (AAO/AOA, 1997). We set both positions out at length, with the population data behind them, in our post on perceptual skills and child development.

What the strong evidence covers is treating the vision problem, not the schoolwork that surrounds it. Of 221 children aged 9 to 17 with symptomatic convergence insufficiency, 73% were successful or improved after 12 weeks of office-based vergence and accommodative therapy with home reinforcement, against 35% on office placebo (CITT, 2008), and a Cochrane network meta-analysis of 12 trials and 1289 participants reached the same conclusion for children (Scheiman et al., 2020). Symptoms and clinical signs were the endpoints. Where academics were measured directly, in 310 children, reading comprehension gained 3.7 points with therapy and 3.8 with placebo (CITT-ART, 2019). We know of no trial that has used spelling as an outcome at all.

Our clinical perspective at Vision & Learning Center, stated as ours and not as proven fact: treating a genuine focusing or eye-teaming problem — the work of our learning-related vision care — removes an obstacle so a child can use good spelling instruction. It is not a spelling treatment, and we do not present it as one. That distinction runs through everything we write about vision and learning.

Signs worth a closer look

• Spelling is far weaker in free writing than on the weekly test.
• Copying from the board or a book produces more errors than writing from memory.
• Letters and words are unevenly spaced, or writing drifts off the line.
• Your child loses their place, skips lines, or rereads to keep track.
• Headaches, eye rubbing, or “the words move” after 10 to 20 minutes of near work.
• Homework takes far longer than the teacher expects for the amount assigned.

Sensible next steps

Start with instruction. Ask the school how spelling is taught, whether phonics, orthographic patterns and word parts are all covered, and whether screening for a language-based learning difference is appropriate. The pediatric technical report on learning disabilities and vision is explicit that the effective treatment for these difficulties is evidence-based reading instruction, built on decoding, fluency training, vocabulary and comprehension (Handler & Fierson, 2011).

Then rule vision in or out. A passed school screening is not enough on its own: the AOA’s pediatric guideline reports that Snellen acuity testing on its own missed 75.5% of the children whose complete examination turned up a binocular or oculomotor problem (AOA, 2017); the same guideline asks for a full exam before first grade, then yearly. If reading itself is also a question, our page on dyslexia explains how we work alongside reading specialists rather than in place of them.

If spelling has been a fight despite good teaching and real effort, a comprehensive developmental vision evaluation will tell you plainly whether vision is part of the picture. Schedule an evaluation in Coconut Creek, Boynton Beach or West Palm Beach, and we will tell you exactly what we find - including that your child’s eyes are working well, if that turns out to be the answer.