Transient astigmatism

Transient astigmatism is a double vision effect that occurs when you reduce too quickly and is temporary, so you should stop reducing and wait for it to disappear.

It seems related to changing cylinder correction in the case of User:User.

Do not get cylinder correction for it, as you would just put extra load on your visual cortex for no reason, slowing down your progress.

If it's too noticeable, you can step up, but if it's not that bad, it's also OK to leave it.