I planned for this to be about windows only, but sometimes found myself searching for things like “mirror mystery” instead of “window mystery” and not even realizing it at first. Maybe it’s just me, but I think, at some level, our brains see mirrors as windows, so I decided to go with it. My interest in the use of windows and mirrors in the genres of mystery and weird fiction quickly grew to include film, art, and everything else under the light of the sun.
There’s a Nancy Drew books called The Hidden Window Mystery (Grosset & Dunlap, 1957) by Carolyn Keen, and Poe’s short story, The House of Usher, in which the windows of a mansion resemble eyes.