Hi. I've noticed that whenever I have a cold, a sore throat, or my asthma acts up and I end up coughing hard, I get this weird blurry, blackish/whitish ring around the edges of my vision, and if I end up coughing really hard, I get "stars" or "spots" in my vision. Kind of similar to the effect that occurs after you look at a bright light for too long. I have astigmatism, so could that be playing a factor, or is this something I should get checked out? Thanks.