What a Drag it is Getting Old

Most of my recent work has involved concentric cylinders and vanes, so loading a sample is a snap.  Recently, I've had to run some parallel plate samples, and I realize that I'm over the proverbial hill, and accelerating downward.  It's harder than I remember to focus on the sample to make sure the gap is completely filled.  It's just another sign that bifocals are in my future.