What is wrong with wearing sunglasses inside?

Nothing, I wear sunglasses all the time. People think it's 'Bad Luck' ....But Rainbow Dash does it all the time :P

I wear sunglasses inside all of the time. I even wear them during my college classes, they never told me to take them off. However, since my eyes are diseased if I do not wear them out in the light even electronic ones my eyes start to water or it looks like I am glaring (I am squinting from the light).

Because you don't need them on... there's no sun inside, correct?

Besides, it looks creepy when they are on inside.