do you use sun glasses whe you reading a book?

hell no! LOL! I sometimes use sunglasses when I am using my computer but not when I am reading a book. We need to have good lighting when reading otherwise our eyes will get stressed and will cause eye defects in the future.

I do not read much at night so I do not use a sun glass. But at other times when I am reading or writing I use my glasses.

I use the sun glasses when I am out, so I could protect my eyes from the heat of the sun. Maybe you mean, the reading glasses? Anyway, when you are reading, it is important that you have a very good lighting so you won't stress your eyes.

i do not see any such possibility except if you are reading while taking a sunbath. the glare of reflecting sunlight from white glossy paper can damage your eyes. it happened to me once but then i stopped reading rather than wearing sunglasses.