Leaving aside dyslexia - although I have had a student who is a GP who is dyslexic - does someone really have to be fully literate to be able to fly?
You don't have to be to drive.
Literacy does not mean being able to read Chinese, Greek or Arabic characters!
Some illiterate people can handle road signs, shop names etc but just can't read a book - or possibly an exam question.
To my mind, as long as they know which side of a line feature to fly on: a) the left; b) the right; c) over the top of. then I don't care if they have to be read the question or have someone else write down the answer!
If you know anyone with disabilities, you'll realise there are many many ways of coping.
I'd rather a pilot who phoned the AIS freephone but couldn't read Notams or work the website (can anyone?) than fly with a Professor of English who just never bothered checking anything.
You can listen to an ATIS to get TAFs and METARs rather than reading them - again, why are they still in code? Make life simple and there'd be fewer mistakes.
Many web pages (actually, all, according to law) should be accessible to voice reading to help blind people - but actually good for others with poor reading skills.
And then navigation. An exam where there is no account of GPS or online flight planners: ie doesn't reflect the real world. And don't talk about writing things down to open cockpit flyers! If you have to write it down, it is a bad message! (and once Edinburgh ATC gave me 16 things to read back in one transmission!!!)
So, perhaps if you have literacy troubles you might be limited to microlights, SSEAs and SEPs in day VFR/VMC.
Perhaps you'll choose to have your spouse or clubmember help you with planning.
Perhaps you'll keep away from complex airspace at first.
Perhaps you'll get a radio licence and learn how to use D&D.
Perhaps you'll not become a commercial pilot.
Or perhaps, like that dyslexic Richard Branson, you might end up owning the airline!