A limbal ring is a dark circle around your outer iris. See below for examples. Then let's see how prominent they are.
@CinnamonGirlE The camera doesn't pick it up as well as when I look in the mirror, but it's there.
@stueytheround
I see it though. They can sometimes fade as we age. Your looks pretty prominent.
@CinnamonGirlE My husband does not have a limbal ring, I do, and both our kids do. Fun with genetics! 🎉
@CinnamonGirlE Yep. It gives my otherwise quite blue eyes a slightly greyer appearance until you take a closer look.