Not the one on my head, but the cap for a highlighter. Was reading my Bible, and had one of those dual-purpose pens. Pen on one end and highlighter on the other. Pen just happens to be white. Used to have a whole bunch of them from an un-named company that makes phone stuff. Came in every training package that you got in the mail.
At any rate, laid the cap down, and when I was done highlighting some things, started looking for the cap. Here I was looking for a white cap on white paper, with almost no shadows. To cap it off, my glasses were off (easier to read without those "inviso" lenses). Now, it was not only white on white, but blurry white on white.
Patted down the bible, thinking it was in the folds, but not so. Finally picked up the bible and decided to put my glasses on. The glasses helped, for there it was, laying just right on that white book cover.
I guess this goes with what John is talking about in 1 John 1, where he says we need to "walk in the light". Got to thinking about there being "darkness" in "light". Don't think so… My photographic experiences say that there are shades of gray as long as there is light. It is only when there is no light that there is darkness.
Try it sometime in the dark wherever you are. You eyes will adjust, and only in the absence of any light will there be real "dark". Yea, I know our eyes (and minds) play tricks on us in the dark, but even a little light adds some form and substance to what's around us.