All of my textures now appear blurry (2D)

I had a huge game that utilized custom 2D sprites and OnGUI text. Nothing was wrong, until today, when I created a new scene to test out some stuff with the text/canvas/event system, and suddenly all textures, in all scenes, appear very blurry and pixelated. I didn't change anything outside the test scene I created. I restarted Unity and it still didn't do anything. Is this a bug? Or is it something I should try to fix?

EDIT: I accidentally scrolled a bit when in play mode, changing the aspect ratio.