I doubt you could show you are Dyslexic when you are not. Most people who think they are are not and never receive any support from the LEA.
I understand how it can be annoying if you "believe" some people cope perfectly fine, a number of students are embaressed by there Dyslexia and wish to remain anonymous in class.
An example of this is a Note taking. During a lesson there maybe someone in there class taking notes for the student who wont sit anywhere near them. So you may think they cope fine, but they are receiving help without your knowledge because people really need it.
What does it achieve though? Employees will not receive extra help and be excused using bad English in the workplace so why should it be tolerated when studying for a degree? Everyone who does a degree should have the same help and the same time to do the exams IMO. If your 'dyslexia' means you aren't capable then so be it, hard luck.
As for getting three grand for a computer, well words fail me.
It seems like every man and his dog is dyslexic nowadays, it is a farce.
Might fake me some results. 
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