Anyhow, I attributed the brow thinning & bare spots to ageing. It seemed to happen right about the time I turned 50. I've said they moved from my brow to my chin. It was right about the time those little buggers showed up.
Maybe the tweezing was it. I still have to tweeze because wouldn't you know it, they didn't disappear from the places I'd want them to.
I use as light of an eyebrow pencil as I can find to "replace" them. The problem is that eyebrow pencils don't come light enough. "Blonde" shows up brown on me. My brows are now much darker than they were before thanks to that.