Oh heck. For me it is the whole Two Faces or a Vase thing. One second I see two faces, the next second I see a vase. My vision has slipped over the last few years, so it takes me a few seconds to focus. Not sure that extending the shadows would necessarily help me, but it might help others.
When nothing is going right and you can't find someone else to blame, start beating your head against the wall, 'cause it'll feel so much better when you stop.