I'm sensitive to the entire Wal-Mart environment, in general. lol Bright florescent lights, crowded aisles, too "spread out" and distractive, etc. I'm not sure what the difference between Target and Wal-Mart is, but I don't get that overload sensitivity so much there.
I've always been sensitive to Florescent lights. The first time I noticed it was in a college classroom. I thought I was having a seizure because I felt so dizzy and disoriented. After that, I started having panic attacks! I thought I was going nuts and went to a psychiatrist who said it was over stimulation and anxiety so I started taking prozac (back in mid-80's) It kinda helped, but I still get "panicky" when I start to feel over stimulated and am now able to "breathe" myself through it much better. My son has the same problem and I've taught him how to do that, but it's still somewhat debilitating because you're always aware that you are easily overstimulated by these things.