It could possibly be the lighting in those large stores and places of work. I can't stand going into places like Walmart, hospitals and etc. I feel kind of light headed to some degree. I always figured it was stray voltage given off by the lights. I do some dowsing work in that area and I hate to say it but, it seems the stroke I had makes me more sensitive to that type of thing. Sounds crazy, I know!
A few other thing I still notice after 7 years (my stroke in 2011), is how I feel going from a well lite room into a dark stairway or hall. The transition again makes me feel slightly light headed and balance is off just a little bit. I always feel like I am tipping to my right side, like I am falling that way, it is ever so slight, but one can notice it!