I wear shades indoors often...I have 'persistent chronic migraines' which, with good meds, are a manageable (mostly) headache w/ light and sound sensitivity.
I have gotten a lot of comments/questions. Some are 'trying to be funny' comments(which, FTR, I don't mine. I claim it's my Yoko Ono impression
), some are intrusive ("Why are you wearing sunglasses" is touch intrusive but I don't immediately rankle at it--although it can be asked in either neutral or incredibly hateful/accusatory/condescending tone of voice), and some are insulting ("what, did you party to hard last night?" "trying to hide your face?")
I don't tend to share my medical reasons but the people who imply, while I'm at work-in front of my boss, that I"m hungover have gotten an (icily polite) earful.