I have about 6-8 pairs of Dollar Store readers lying around the place, some in vehicle, and some in my tackle bags. I used to wear a pair on a neck lanyard when I was still working, but quit using those after retirement because I don't wear the readers to drive, watch TV, fish, or much of anything other than when on the computer (& occasionally when viewing texts on my phone).
If you already have readers & just forget to take them ... the lanyards are the cheapest way to go.