Vision therapy is often used to treat problems with how the eyes track, work together, or how vision is processed. Some children who have been diagnosed with a learning disability like attention deficit hyperactivity disorder (ADHD/ADD), dyslexia, or dysgraphia have underlying visual problems that contribute to their symptoms.
Example 1: A study (view here) found that kids who had problems with vergence (eye teaming) had reduced ADHD scores after treatment.
Example 2: Another study (view here) found statistically significant improvements for reading comprehension and reading composite score in children who were treated for convergence insufficiency
I was told vision therapy cannot treat learning disabilities...
Many professionals will argue that vision therapy cannot treat a learning disability, and in the purest of definitions, they are correct. This is because the true definition of a learning disability means that vision has been completely ruled out. The problem is that most kids are diagnosed with a learning disability like dyslexia before vision is completely ruled out. Many of them have a vision problem that completely mimics dyslexia, others may have true dyslexia and no vision problems, while some will have a combination of the two. You can't tell until you properly test the visual function.
Perhaps the easiest way to think about it is if your child was having trouble with being tired, you would want to rule out low iron before they were diagnosed with chronic fatigue syndrome (which means that there is no known reason for fatigue)
Now imagine hundreds of children with fatigue skipped the iron test and were just labeled as chronic fatigue. Some of those children would have true chronic fatigue, but many of them may just be iron deficient and received a pre-mature diagnosis of chronic fatigue.
Technically, giving a child iron supplements should not be able to treat chronic fatigue. However, for all those kids where the iron levels were overlooked the iron would be very successful in treating the chronic fatigue.
Vision therapy and learning disabilities is the same as iron and fatigue. Many learning disabilities are caused (in part or whole) by vision problems that are undiagnosed, and some have eye tracking that works perfectly. If there is no vision problem, then vision therapy will not help.
If there is an undiagnosed vision problem causing the struggle, then vision therapy is very successful in helping the child.
Vision therapy can be a tremendous help for a child's reading if vision is part of their struggle, but you can't tell until you have it tested. If your child, or a child you know is struggling, please make sure they get their eye tracking, teaming, and visual processing tested. It could change their life.