Chinese windows used to be covered with paper. Plenty of light gets through, although you'd have to open the windows or actually go outside to see what's outside. (Apparently, viewing the outside in the comfort of your bedroom is a luxury that most people don't need.)
In warmer regions, people would just tear out the paper in the summer and apply new paper before winter.
I may have glass windows, but usually they are covered up with blinds and or curtains. Especially in the bedroom. It's nice to be able to open them up and let light in when I need to, but I wouldn't put it on a list of necessities.
In warmer regions, people would just tear out the paper in the summer and apply new paper before winter.