Thanks, John, as usual I didn't ask the question properly, let me try again. There is a chunk of space that is in focus when a camera is at a specified aperture. What I couldn't remember was (what you are essentially saying is true) that when the aperture gets smaller, the chunk of space in focus not only increases outwards into the distance, but also closer to the aperture, thus making it easier to read a text without your reading glasses.

yours, Peter T.