Recently I wrote a piece about defining dyslexia ( ), frustrated by the constant refrain heard by parents, “Well, we really don’t know what it (dyslexia) is.”   What is puzzling to parents is the statement that they often hear, “I don’t see it with your child in the classroom.” 

Diagnostically, one does not “see” dyslexia. The only way that I know to identify dyslexia is to listen to it, not see it.
Take Sari, age 17, a child I recently evaluated who was never diagnosed with dyslexia. 
When I listened to Sari read I was struck how strained her reading sounded.  Larger words such as, conspicuous, philanthropist, mechanic,  represented hurdles in the text that she had to jump over. Every time she hit one of these “low frequency” words, she slowed down her reading to a crawl and either read the word correctly by laboring through or substituting some sort of nonsense word that altered the text. Either way, the reading was very tough sledding for Sari. She derived little meaning from what she read.
The problem is her teachers have never really heard her read. From early elementary school the majority of reading activities are done silently. Sari was never diagnosed with dyslexia because no one was listening for the signs and symptoms.  
Unless children read words (real words and pseudowords) in isolation followed by context oral reading, no one would know Sari had a reading disability. She was simply smart enough (and well behaved enough) to fake it.
Let me leave you with this: If I ask you what’s “5 + 3” do you have to think about it or figure it out? 
My guess is, no.
Now try and read these words:   
·         mechanic
·         thrumblit (a made up word)
·         Riconsetti (a name)
By middle school, adequate readers can read these words as easily as adding “5 + 3” – automatically and effortlessly.
With dyslexia, these words are a chore, resulting in much reading resistance.
To “diagnose dyslexia” listen to the strained reading. 
It’s not something that you will see, but hear.