[foldr]

No, my prescription is for astigmatism, and my contacts are contacts specifically for astigmatism. In my experience, they orient themselves (and indeed I have never had to worry about their orientation).

I have never previously thought about this in terms of rotation (as I was not even aware that the contact lenses were asymmetrical), but I do normally have to blink a few times after inserting the contact lens before I have sharp vision. But in my experience it takes a few seconds for this to happen and does not depend on inserting the lens at any particular orientation.

I have glasses too, so I would notice if the contact lenses were giving me significantly worse vision!

The brand is '1 Day Acuvue Moist for Astigmatism'.

[_yb2s]

It might be different for different people, but if I don't align mine, it takes more than a few blinks to align them. I think they will eventually but it could be a very long time (hours?)