Single and ready to mingle (with your frames)
Single vision lenses do one job and do it well: correct your eyesight at one distance. That could mean fixing nearsightedness or farsightedness, but not both. If you have astigmatism, they can help with that, too.
Want to double-check this is the right lens? Pull out your prescription and look at the ADD column. If it's blank, single vision lenses are for you.