The perceptual system uses at least two strategies to recognize words:

 
1) A word outline or 'mask'
2) The letters of the word.

As these are used together they are a kind of mix between the two. We see this demonstrated when reading sentences with numerous errors ~ we read over the errors.

I came across the secret when trying to program a computer, an old green screen computer programming in Basic. An error message kept popping up and as I knew what the error was I dismissed it very quickly.

But then I started to wonder what a strange word in the error message was: bdbdosbb.bds or something like that.

So the next time it came up I looked for it and could not find it. But then I saw it. The word was 'bdos' but just above it was another word, a file name. I don't recall the name of the file now but it was in the 8.3 format, eight letters, dot, three letters.

Part of my dyslexia, it seems, takes the mask from one word and the letters from another word and puts them together, resulting in this strange combination that I must have seen 100 times a day over months.

With that key I then went on to discover correlations to other errors in my dyslexia and why masking the lines above and below the one you are reading works so well for dyslexics (this is a common method).

At least one form of dyslexia, then, occurs when the mask or word template, the 'holistic' image and the letters are merged from different words.