Why have I been using a paintbrush on my iPad?

I'm not the greatest artist in the world, but I do like to tinker with a bit of sketching. When my vision deteriorated to the point of this becoming difficult, I turned to my iPad for assistance. Using a stylus and a drawing app I found I was able to continue sketching. The ability to magnify the canvas to whatever was comfortable for me has, quite literally, been an eye opener.