I have a little gadget that attaches to my mike stand. This all helps me get up to speed very quickly and at least to a stage when I can perform the songs in public. I find the more I play the songs in public the less I need the prompts.
Indeed, part of this discussion is a "which came first, the chicken or the egg?" consideration. I find that practice decreases my dependency on visual aids... but time in front of an audience is a necessary part of that practice. and it's something you can't get from practicing at home.
The visual aids give me the confidence I need to face an audience. If the material had to be completely memorized before I got on stage, at age 62 that would effectively undermine my goal of performing. Ever.
I don't want to end up as one of those people who practices forever and never performs.