Yes, I've had the vision problems many times during a panic attack. I think it's because we breathe so shallow during one that we may not be getting enough air. I highly doubt it's your medication since it only happens when you have a panic attack.
The vision only accrues after body whole body tingles and my breathing is hard to control.
I have never heard of the vision reaction to panic, check the side effects of xanx for a start and discuss with your doctor.