"A rectangle with sharp edges takes indeed a little bit more cognitive visible effort than for example an ellipse of the same size. Our “fovea-eye” is even faster in recording a circle. Edges involve additional neuronal image tools. The process is therefore slowed down.” Professor Nänni is saying that rounded rectangles are literally easier on the eye. Put another way, compared to square-edged rectangles, rounded rectangles are more computationally efficient for the human brain. To me, this is a revelation. An idea that at the very least demands more investigation." - Rob Hoeting from Bookmarklet