Somehow I managed to activate a display where I see a lot of dots (normals?) when I'm in edit mode and the object is subdivided.
The image to the left is without the subsurf, and the right is with it on, but I still want to "Display modifier in viewport".
This only happens in Face select mode, but I don't remember it looking like this...?
It doesn't happen when I create a new object, so it seems to be an object setting. I think I have pressed a shortcut but mistake somehow...