Signatures of Blind People

I went looking for examples of the signatures of people who had long been blind and found some interesting things.  For example, these dated signatures by Helen Keller

It says "secretarial signatures," but I suspect the signatures were in her own writing.  Here is an example of her handwriting from much earlier.

I suspect she was using some kind of form to write within, such as the one my father used when he had to sign things,  my mother absolutely refused to sign documents in his place.  

Here are two signatures listed as being George III before and after he went blind and was suffering from mental illness.

I don't know what it tells you about the six accepted signatures of the Stratford money-lender and broker, but none of them look as fluent to me as these.  No one would accuse George III of having been a good or great writer or of even above average intelligence but he knew how to spell his own name.  Helen Keller was, of course, very intelligent and an educated intellectual, as whoever wrote the plays and poems attributed to Shaksper(e) would have had to have been.