We can only read them because we know what the original spelling is. A dyslexic kid just starting out to read and write, would have no prior knowledge of words

We can only read them because we know what the original spelling is. A dyslexic kid just starting out to read and write, would have no prior knowledge of words to refer to. If we don't know what the correct pronunciation for a word is, or its spelling to start with. All the best trying to read or write with such a condition.