The Bookchart concept goes well beyond a place to put stuff.  Eyestrain is eliminated by keeping the workpiece, chart, thread, and embellishments close to the same focal distance from your eyes. The eyeball's shape and aim changes when close focal distances change; like any muscle, the frequent movement can lead to the muscle straining rather than just stretching and snapping back (like in younger eyes).  If you do not have a prescription eyewear,  Inexpensive 2.5 to 3 diopeter reading glasses and Bookchart combined can work wonders.