I get this, but it comes and goes. Sometimes my eyes go a bit blurry and that really scares me, but I try not to panic and wait a couple hours, then it seems to go away.
I read somewhere when you are having a panic attack, your pupils dilate to make you more aware of your surroundings (flight or fight), so you get a bit blurry. Also all the energy and blood is moved to your vital organs to suppport them, so other things miss out - like you get nauseous because the body is using the energy from digestion to make you run faster (if you had to run).
I also find it worse if I don't sleep well at night.