More than portals to the world

Panes of glass have allowed humankind a material for physical and philosophical utilization.  We look through them.  We are seen through them.  Some are colored.  Some distort views.  Finding quotes over the past 9 weeks have allowed me windows into different points in time.  So the last theme for this challenge is windows.

“Many a doctrine is like a window pane. We see truth through it but it divides us from truth.” - Kahlil Gibran

“A house without books is like room without windows.” - Horace Mann

“I need no dictionary of quotations to remind me that the eyes are the windows of the soul.” - Max Beerbohm

 “Habit is habit, and not to be flung out of the window by any man, but coaxed downstairs a step at a time.” - Mark Twain

 How do you use windows?