Vision and ADHD

See also our article on Vision and Dyslexia.

In 2013, a very smart Vision Mechanic by the name of Patrick Quaid published a study on the role of vision in the appearance of learning and reading concerns. In Ontario, children who meet sufficient criteria are ‘coded’ and put on an IEP, or Individualized Education Plan. Dr. Quaid was looking for patterns – what are the visual signs associated with reading and learning concerns.

Not surprisingly, the study revealed that by far, students flagged as struggling with learning and attention problems were also very likely to also have fairly obvious visual impediments as well. Many of these kids could see just fine but still had trouble with other aspects of vision which are known to lead to difficulties in scanning, focusing, or concentrating. Addressing these obstacles almost always leads to improvement in academic performance and standing.

From the study:

Conclusion: This research indicates there are significant associations between reading speed, refractive error, and in particular vergence facility. It appears sensible that students being considered for reading specific IEP status should have a full eye examination (including cycloplegia), in addition to a comprehensive binocular vision evaluation.

(“Association between reading speed, cycloplegic refractive error, and oculomotor function in reading disabled children versus controls ” Graefes Arch Clin Exp Ophthalmol (2013) 251:169–187)

There are many ways vision can interfere with learning, development, and mental focus. More common concerns include farsightedness, astigmatism, and convergence insufficiency – all easily detected and treated, but invisible to the untrained eye. Many other studies since have shown similar effects on reading and learning due to various visual concerns, and eyesight has less to do with things than most people would guess.

In a computer-based classroom where the only means of learning is to be efficient at scanning text, something like 1 in 4 children struggle just managing the visual input. Of children identified as having a learning, reading, or attention deficit, the majority will have some sort of visual functional problem that is contributing to it, or simply is the cause. From Dr. Quaid’s paper:

“…study looked at 266 ADHD cases, and found a three times higher prevalence of binocular vision dysfunction (convergence insufficiency) in the ADHD group compared to population normal values. Of particular interest was the observation that five out of the nine DSM-IV criteria re- quired for the diagnosis of ADHD overlapped with symptoms of binocular vision dysfunction. The potential for diagnostic confusion was discussed, and it was suggested that whilst there are cases of ADHD with no binocular vision dysfunction present, due to the increased incidence in the ADHD population, binocular vision issues should be ruled out. “

(Granet DB, Gomi CF, Ventura R, Miller-Scholte A (2005) The relationship between convergence insufficiency and ADHD. Strabismus 13:163–168 )

It is a relatively easy thing in clinic to induce, or demonstrate Visual Impediments to Learning and Development (VILD). We can also reasonably easily conclude that things will improve for the student once core functions are restored and vision is fully re-integrated and responsive. In the end, if the foundation is strong, it should be no problem to build wonderful and elaborate cognitive and motor skills on top of that.

You can learn a lot more about eyes and vision at Our course on Human Vision will fill you how vision works, and how it can throw us for a loop when it doesn’t. You’ll be especially interested in spending time with us if you’re a parent, a teacher, therapist or doctor working with reading, developmental, and learning disorders, or even brain injuries.

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All science, with just a little attitude and no filler. That’s the Vision Mechanic. See you next time.

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