March Challenge - Tenebrous/simplicity5

Day 5 of DDW's March daily challenge and a dip into LittlestDragons's simplicity challenge - Tenebrous/simplicity5

The weather today (unco-operative as ever) was as far from dark and murky as you can get, so I couldn't use that for the theme. I did check out any other meanings for the word and it can also mean obscure, so apart from some of the contents of my bookshelves and CD collection, I was struggling with that.

Back to the dark/murky definition then. Some time ago when I was having 6 monthly changes in my glasses prescription I had a pair of prescription sunglasses made up by an on-line supplier, I specified the darkest non-polarised lenses I could get, but they arrived with polarised lenses. However, I didn't bother following it up as I only expected to use them a couple of times before needing another prescription. Typically, they have had to last longer than that, but while in Yosemite one of the lenses came out. The screw thread seems to be worn, and the ones from my spectacle repair set are the wrong ones, it must be quite an obscure thread. So, this is the lens that came out - it is dark (it would have been murky with my fingerprints all over it if I hadn't cleaned it up) and held in with an obscure threaded screw. All very Tenebrous - not to mention tenuous!

Taken with the phone camera and unprocessed as part of the simplicity challenge.