What are the Different Degrees of Dyslexia?
Whether you have a loved one with known or suspected dyslexia, or have an interest in the topic for other reasons, many people ask about the different degrees of dyslexia. After all, dyslexia is a learning challenge that comes with a lot of anxiety or questions. People usually want to know what the overall prognosis is, assuming that the person with dyslexia is given proper interventions.
A major part of this discussion, though, is the severity of someone’s challenges. These difficulties can be mitigated upfront with compensating strengths or a high level of intelligence. So, while there are no official “degrees” of dyslexia, it’s best to think of this question in terms of how difficult it is for someone to learn how to read and write, master foreign languages, or perform everyday tasks.
What is dyslexia, anyway?
In a nutshell, dyslexia is a condition where someone has difficulties with reading and writing-based tasks, even though they have received competent classroom instruction, and don’t struggle as a result of other conditions such as visual impairments. Whether or not someone is having difficulties (or achieving at a lower level than expected) must be measured against their level of overall education and age. This means that someone who’s 16 years old and in secondary education can receive the diagnosis at a much higher level of reading or writing proficiency than a primary school student aged ten.
With that said, the challenges that are associated with dyslexia often carry over into other areas of life beyond school. Or even within the school context, it can affect more than just writing and reading-related subjects. For instance, a student with dyslexia who is very good at mathematics might have difficulty with “story problems,” since these require significant reading comprehension. In addition, if someone has trouble reading then it can be more difficult to pursue a hobby. People that have different degrees of dyslexia can experience challenges in life at different levels, as well.
Types of dyslexia
All that being said, there are different kinds and causes of dyslexia. The neuroscience behind it is still emerging, in that scientists still can’t give someone a medical test and know immediately if they have this condition. Existing theories are beyond the scope of this article, but understanding the “type” that someone has helps determine interventions and gives insight on the ultimate prognosis.
Primary
This is the type that most of us think about when we hear the term “dyslexia.” Recent studies have found that it is the result of the left half of someone’s brain not working correctly, especially in the areas that process language. It isn’t a kind of brain damage, though. Think of it as a different trait that makes certain things more challenging than average, in contrast to other “differences” like having a good sense of color that make something easier.
Why do people develop primary dyslexia? Simply put, it’s genetic. This trait can be passed down from one generation to another, similarly to a predisposition for cancer or heart disease. Fortunately, though, adequate intervention will allow most people with dyslexia to graduate high school. Many people even go on to college, and hold down high-paying jobs. It is only people with the most severe degrees of dyslexia, or who don’t get adequate help in school, that significantly struggle in adulthood.
Secondary
Secondary dyslexia happens when something goes wrong in a developing fetal brain that makes the child not process language quite right. It’s similar to a birth defect in this sense, though we don’t know why it happens. Luckily, secondary dyslexia is like a minor developmental delay: with proper intervention, the impairment can completely disappear. From a layman’s standpoint, it can look like someone just took longer to “get the hang of” reading or writing.
Acquired
Finally, there’s acquired dyslexia. This is the result of a brain injury or other illness, and it can occur at any point in life. While the other kinds of dyslexia discussed here make it difficult for children to learn how to read and spell, this one results in some loss of reading ability. It’s similar to the way in which people can have trouble speaking after a stroke or lose memory due to dementia. Fortunately, people can sometimes “relearn” to read at some degree.
Different types of impairments that result from dyslexia
For most people who ask about the “degrees” of dyslexia, they are referring to the type and severity of actual impairment rather than the cause. In other words, what tasks does this person find most challenging, and how severe is the challenge. Here are the major areas where people with dyslexia struggle, along with their technical terms.
Phonological dyslexia
If you’ve ever seen a child trying to “sound out” a word but having more trouble than the other members of the class, then you’ve seen phonological dyslexia. This is a difficulty with “coding,” or associating letters and words with their sound and therefore, linguistic meaning. For example, let’s say the student has trouble decoding the word “cat.” C-A-T is the spelling, and the sounds are “k”, soft “a”, and “t.” Like the furry animal that loves to chase mice. Someone without dyslexia will soon learn that the “c” makes the same sound as “k” in many situations. But if someone has dyslexia, it’s much harder to learn this basic principle.
Conversely, if someone with dyslexia is learning to spell “cat,” they might want to spell it as “kat” because they associate “k” with the first sound in the word. Luckily, although this student will get the item wrong on a spelling test, someone reading “kat” will know that the writer means “cat.” That’s because the sound is correct.
Surface dyslexia
Surface dyslexia describes a difficulty where someone finds it harder to master “sight words.” These are words for which the spelling isn’t obvious from a phonetic standpoint. In English, examples can include “February,” “Wednesday” and (for UK English) “labour” or “favour.” Often, these sight words have silent letters or include exceptions to the typical spelling rules, which makes them harder to know anyway.
To learn sight words, the average person simply memorizes the spelling. This is also a common approach to reading in foreign language instruction. They’ll teach grammar, but vocabulary is often built using sight words. Surface dyslexia is much less common in general, and usually is a feature of acquired dyslexia. However, it does develop in children occasionally.
Deep dyslexia
Finally, there’s deep dyslexia. This is always caused by brain damage on some level. When someone has deep dyslexia, they do two major things: make semantic errors (“house” becomes “shed”) or they “misread” the word by thinking it’s something else (“bread” could become “lead”). This is in contrast, though, to more typical reading errors. Someone who mistakes “to, two, and too” is dealing with a typical reading and grammar mistake.
In many cases, someone with deep dyslexia doesn’t see the word properly. This would be a perceptual error (think about when you say that your eyes are “playing tricks” on you). It can also manifest because the person doesn’t recall previously learned words, substituting what they “think” the word is supposed to be. Ironically, some of the common stereotypes of people with dyslexia, such as the idea that they see things backwards, are based on the errors people with deep dyslexia make.
Any combination of the above
Keep in mind, it’s possible for someone to suffer from more than one type of dyslexia. A rare, but possible, combination is phonological and surface dyslexia. This can happen when a child has dyslexia because of genetics or abnormal fetal formation. Then, they later suffer a head injury or illness, causing surface dyslexia. Or, for that matter, suffer a brain injury during labor and delivery.
So how does this determine a “degree” of dyslexia?
When parents find out that their child has dyslexia, a common question is, “how bad is it?” What they often mean is, “how hard is it going to be for my kid to learn how to read,” or alternatively, “can my child graduate from high school.” The fact is that everyone with dyslexia has a different mosaic of gifts and challenges, each of which can affect their prognosis. Let’s look at this in more detail.
Each impairment type can have different degrees of severity
Most educators will tell you that dyslexia is a spectrum condition, with all impairments ranging from mild to severe (or nonexistent). No two people with dyslexia are the same in terms of strengths and weaknesses, any more than their personalities or physical traits match. Although there are key features of dyslexia in general, it’s important to map out the specific challenges each person faces. Then, interventions focus on addressing the individual’s needs.
It’s more complicated, though, than just what difficulties someone does or does not have. Rather, both the combination and severity of impairments must be taken into account. For instance, one child might have trouble distinguishing “P” and “b,” which is common, while another might do OK distinguishing letters while struggling to string them together properly. At the same time, the person who has trouble putting letters together might only struggle with longer words, or words that have specific letter combinations. Or, he might struggle with a bit of everything and need more support. We’d say that the latter impairment is more severe than the former.
The presence or absence of one impairment type influences the degree of dyslexia
Because phonological dyslexia is the most common form, educators and psychologists have more experience with interventions. In many cases, we can address mild to moderate phonological dyslexia with multi-sensory teaching methods. These can be used both for the child’s primary language of instruction and for foreign languages. In practice, this means that many children, especially those with milder degrees of dyslexia, can still meet foreign language requirements in high school or college.
Here’s the even better news: in many cases, learners with dyslexia can master reading with relatively minor adjustments to instruction. In addition, there are supports such as audiobooks and note taking assistance, that can help level the playing field. These are especially useful later in a student’s academic career when schoolwork requires more and more reading and writing.
With that said, if a student has more different types of deficit, or if a single deficit is more severe, one can say they have a higher level of dyslexia. Each deficit must be addressed individually to maximize success. At the same time, milder deficit levels are easier to teach around or accommodate than severe ones. The goal of instruction and modifications is always to maximize someone’s ability to read, write, or achieve on an academic level. In addition, schools must prepare students to be successful in adult life.
Sometimes, dyslexia goes unnoticed
With the milder degrees of dyslexia, and in cases of high intelligence, the condition can sometimes go unnoticed. There are several reasons for this, such as schools mistaking dyslexia for other challenges, such as ADHD. Another common cause of a student falling through the cracks is a high level of intelligence. In this case, the student will find a way to compensate in other areas, thereby successfully learning to read and write. With a very minor level of impairment, the intelligence required to “compensate” is lower. However, either way the child needs significant motivation to succeed.
The sad thing about a mild degree of dyslexia which goes unnoticed is that the result is often very frustrated students. After all, they work harder for the same results as “typical” students. A lot of kids also give up on school because they just can’t cope with the work. In addition, having trouble pronouncing words can make a child feel “stupid” and experience bullying. This is why diagnosis and intervention are so important, even for those with milder impairments.
Dyslexia is a spectrum condition where symptoms range from almost unnoticeable to very challenging. Fortunately, with proper diagnosis and intervention there’s a high probability that someone can live a normal life with a regular job. With that said, the most important thing is that the adults in a child with dyslexia’s life are supportive. Parents, in particular, can help children learn resilience and determination. Combined with the right instruction, determination helps ensure that even more severe degrees of dyslexia aren’t the end of the world.
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