Dyslexia is a neurodevelopmental disorder that primarily affects the ability to learn to read accurately and fluently. This condition is rooted in a deficit in phonological processing—the brain’s ability to recognize and manipulate the sounds of spoken language. The disorder is not related to intelligence or vision problems, but involves a different way the brain processes written and spoken language. Observing a person with dyslexia read reveals distinct struggles that highlight the immense cognitive effort required for a task that is automatic for most people.
Decoding and Word Recognition Difficulties
The most fundamental struggle observed is difficulty in decoding, which is the process of translating written symbols into speech sounds and words. Individuals with dyslexia often struggle with the alphabetic code, failing to consistently link letters or letter combinations to their corresponding sounds. This phonological awareness deficit makes “sounding out” unfamiliar words a difficult task that leads to frequent errors.
A person may be seen making frequent mistakes such as substituting, omitting, or adding words as they read aloud. For example, they might transpose letters within a word, reading “saw” as “was,” or confuse visually similar letters, such as ‘b’ and ‘d’. When encountering multisyllabic words, they may omit whole syllables, such as reading “transferable” as “transable,” because the mental energy required to link the initial sounds is exhausting.
Instead of decoding each word, a reader may attempt to guess based on context or the first few letters, especially when the text contains sight words. This means the reader is expending significant cognitive effort simply to recognize a basic word, a process that should become effortless and automatic. This labor-intensive reading strategy is a persistent characteristic of dyslexia, even in adulthood.
Fluency and Reading Rate
The constant struggle with decoding results in a lack of smoothness and speed during reading, leading to a slow and laborious pace. A person reading aloud often exhibits a halting, word-by-word pattern, which is the exact opposite of the effortless pace of a skilled reader.
Eye-tracking studies confirm this effortful strategy, showing that readers with dyslexia make more and longer stops (fixations) on words. They also make shorter eye movements (saccades) between words, suggesting they process less text at a time compared to fluent readers.
The reading may lack prosody, meaning it is delivered without appropriate expression, rhythm, or intonation because the reader’s attention is focused almost entirely on word recognition. This preoccupation with individual words can lead to a frequent loss of place on the page, sometimes resulting in rereading lines or unintentionally skipping them.
This slow rate and effortful tracking may cause a person to use a finger or marker to maintain their place on the page. Visible signs of frustration or physical discomfort, such as excessive head movement or squinting, can also be observed as the reader attempts to maintain pace and focus.
The Impact on Reading Comprehension
The high cognitive load demanded by the mechanical act of decoding and maintaining fluency often impacts comprehension. Since so much working memory capacity is dedicated to translating letters into sounds, there are fewer resources available for processing the meaning of the words and sentences.
This phenomenon is often described as “reading but not understanding,” where the person successfully reads the words aloud but cannot summarize the content immediately afterward. The difficulty in retaining the meaning of the text is particularly noticeable with longer or more complex passages because the memory resources are exhausted before the full context can be integrated.
While the decoding process itself is the primary cause of comprehension issues in dyslexia, some individuals may also struggle with higher-level skills such as making inferences or following complex narratives. For a person with dyslexia, silent reading is typically just as slow and taxing as reading aloud, continuing to draw heavily on cognitive resources.
It is important to distinguish this secondary comprehension problem from a general language comprehension disorder, as individuals with dyslexia often have strong listening comprehension skills. The struggle is not with understanding language itself, but rather with the cognitive strain imposed by the inefficient and laborious process of extracting that language from the written text.