I was concerned that I might have given him wrong information. I sometimes go into choice paralysis when having my eyes tested.
Optician (putting another lens into the spectacle frame): "Is that better or worse?"
Me: "Er... I'm not sure. Could you just take it out for a moment? Um... No, it was better. I think. Could you put it back again. Yes, I think it's better." And so on and so on.
Anyway, all was well. After checking his notes, he realised he had written down my old prescription with the new astigmatism values. So that's OK then. Except I have to wait another ten days or so for the corrected specs to turn up. Sigh.