On December 1st, broke out a new pair of lenses (I'm on one-month disposables) and suddenly the blur attacks are gone. I can only suppose that I must have had an incorrect lens ... right packaging but incorrect contents (I use the same strength in each eye, so no, I wasn't putting the wrong one in) ... I'm guessing it was the wrong size rather than the wrong strength, since I could see properly and clearly when the blur wasn't happening (the hard blink clarifying things would be because doing that repositions the lens on the eye).
Most of me is relieved, although a part is a little disappointed ... it could have been a signal that the final traces of astigmatism had vanished and I was down to being blind due to 100% near-sightedness instead of multiple reasons. :p